SLC6A2 gene and attentional performance before and after medication in children with ADHD.Dysregulation of noradrenergic system may play important roles in pathophysiology of attention-deficit/hyperactivity disorder (ADHD). We examined the relationship between polymorphisms in the norepinephrine transporter SLC6A2.Fifty-three medication-naïve children with ADHD were genotyped and evaluated using the continuous performance test (CPT). After 8-weeks of methylphenidate treatment, these children were evaluated by CPT again. We compared the baseline CPT measures and the post-treatment changes in the CPT measures based on the G1287A and the A-3081T polymorphisms of There was no significant difference in the baseline CPT measures associated with the G1287A or A-3081T polymorphisms. After medication, however, ADHD subjects with the G/G genotype at the G1287A polymorphism showed a greater decrease in the mean omission error scores (p = 0.006) than subjects with the G/A or A/A genotypes, and subjects with the T allele at the A-3081T polymorphism (T/T or A/T) showed a greater decrease in the mean commission error scores (p = 0.003) than those with the A/A genotypes.SLC6A2 in methylphenidate-induced improvement in attentional performance and support the noradrenergic hypothesis for the pathophysiology of ADHD.Our results provide evidence for the possible role of the G1287A and A-3081T genotypes of  Attention-deficit hyperactivity disorder (ADHD) is a disorder primarily characterised by inattention, impulsivity, and hyperactivity, with a worldwide prevalence of 5.3% . It has Although the aetiology of ADHD is not fully understood, there is evidence that dysregulation of the central noradrenergic system and the dopaminergic system may be involved in the pathophysiology of ADHD ,4. The cSLC6A2) that codes for NET, located on chromosome 16q12.2, is a candidate gene for association with ADHD [The gene  and response time variability of the CPT in 364 individuals from 152 families with at least one child diagnosed with ADHD. However, in a study by Cho et al. [Noradrenergic dysfunction related to norepinephrine transporter-mediated mechanisms may be associated with cognitive impairments in ADHD. The continuous performance test (CPT) is one of the most widely used neuropsychological tests in ADHD. The test assesses several aspects of attentional performance, including sustained attention in response to target stimuli and inhibitory control in response to non-target stimuli . A meta-o et al. , there wo et al.  reportedSLC6A2 and MPH-induced changes in CPT. To our knowledge, there have been no studies of the association between SLC6A2 and MPH-induced changes in CPT. An examination of such an association would inform the roles of the genetic polymorphisms of SLC6A2 in the effectiveness of MPH treatment on core deficits of ADHD and further clarify the roles of the noradrenergic systems in the genetic basis of ADHD. Thus, we examined the relationship between the presence of the G1287A or A-3081T polymorphism within the SLC6A2 gene and CPT measurements before and after 8 weeks of MPH treatment in children with ADHD.Considering the associations between NET genes and the response to MPH treatment or CPT measures previously reported, we propose that there may be an association between the polymorphisms of We recruited 53 children with ADHD from a child psychiatric clinic at Seoul National University Hospital in South Korea. Inclusion criteria were 1) diagnosis with ADHD according to the DSM-IV criteria, as ascertained by a child psychiatrist; and 2) age 6–18 years. Exclusion criteria were 1) any other mental disorders except for mild oppositional defiant disorder and anxiety disorder not requiring medication; 2) a past or present history of neurological illness; 3) an IQ below 70; 4) learning disabilities; 5) any history of substance abuse; and 6) previous treatment with MPH. All participants were drug-naïve at the time of study entry. To diagnose ADHD and any comorbid disorders, we used the Korean Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version (K-SADS-PL) . We asseBefore medication, parents of participants completed an attention-deficit hyperactivity disorder rating scale (ADHD-RS), and participants underwent CPTs. Subjects received 0.35 ~ 1.77 mg/kg/day MPH  for 8 weeks. Doses were adjusted depending on each patient's symptom severity and drug tolerability. The mean dose of MPH was 0.86 (SD 0.29) mg/kg/day. The maximum dose was 54 mg/day. All subjects took medications once per day in the morning. After 8 weeks’ MPH treatment, the ADHD subjects underwent the CPT again. On the day of the CPT, patients were instructed to take MPH in the morning as usual.This study was conducted as part of a Health & Medical Technology R&D program and was approved by the institutional review board (IRB) for human subjects at the Seoul National University Hospital. Parents/guardians provided written informed consent, and the children provided verbal assent to participate in this study.We used a computerised CPT  to measuGenomic DNA was extracted from whole blood lymphocytes using a G-DEXTM II Genomic DNA Extraction Kit . The detection of a single nucleotide polymorphism was based on an analysis of primer extension products generated from previously amplified genomic DNA, using a chip-based matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry platform .SLC6A2 polymorphisms were genotyped as previously described [2, 0.2 mM of each dNTP, 0.1 U HotStarTaq Polymerase , 8 pM of each primer, and 4.0 ng of genomic DNA. The program consisted of denaturation at 95°C for 15 min; followed by 45 cycles at 95°C for 20 sec, 56°C for 30 sec, and 72°C for 1 min; with a final extension at 72°C for 3 min. Following the PCR, unincorporated dNTP was removed by the addition of 0.3 U of shrimp alkaline phosphatase and incubation for 20 min at 37°C, followed by 5 min at 85°C for enzyme inactivation. The total volume of each reaction was 9 μl, including hME enzyme , ACT termination mix, and 5 μM of extension primer. The primer extension protocol was started at 94°C for 2 min, followed by 55 cycles at 94°C for 5 sec, 52°C for 5 sec, and 72°C for 5 sec. After desalting the reaction products with SpectroCLEAN (Sequenom), samples were analysed in the fully automated mode with a MALDI-TOF MassARRAY system .The escribed  with sliχ2 test.Allele frequency was determined, and the Hardy-Weinberg equilibrium was calculated using a goodness-of-fit Due to the small number of individuals with the A/A genotype for the G1287A polymorphism, the subjects were dichotomized according to whether or not they possessed the rare A allele (recessive model). For the A-3081T polymorphism, which follows a co-dominant inheritance pattern, subjects were dichotomized according to whether or not they possessed the T allele, and this methodology was based on our previous study that found an improved response to MPH treatment in ADHD subjects with the T allele as compared to those without .t-test. Between-group comparisons involving categorical data were assessed using the χ2 test or Fisher’s exact test. The association between the evaluated genotypes and the neuropsychological measurements was investigated using a one-way analysis of variance (ANOVA) or independent two sample t-tests. Between-group differences according to genotype were assessed based on the percent change in the CPT measurements [Group differences in the clinical variables involving continuous data were computed using an independent two sample Of the 53 subjects in this study, 45 (84.9%) were boys and 8 (15.1%) were girls. According to the DSM-IV criteria, the combined subtype is the most common , followed by the inattentive  and hyperactive-impulsive  subtypes.SLC6A2 revealed that the G/G genotype was observed in 31 subjects (58.5%), the A/G genotype in 19 subjects (35.8%), and the A/A genotype in 3 subjects (5.7%). The A-3081T genotype analysis of SLC6A2 revealed that the T/T genotype was observed in 12 subjects (18.9%), the A/T genotype in 28 subjects (52.8%), and the A/A genotype in 13 subjects (24.5%). The distributions of the genotypes for the G1287A and the A-3081T polymorphisms were in agreement with the expected values of the Hardy-Weinberg equilibrium .The G1287A genotype analysis of Table G1287A polymorphism showed more improvement in the mean omission error scores (p = 0.006) than those with the A/G or A/A genotypes. Subjects with the G/G genotype showed the greatest decrease in omission errors, flowed by those with the A/G genotype and the A/A genotype (p = 0.023), although the small number of subjects with the A/A genotype limited statistical comparisons among the three genotypes  at the A-3081T polymorphism showed a greater improvement in commission errors of the CPT than those with the A/A genotype.No differences in pre-treatment CPT performance were associated with the G1287A or the A-3081T genotypes, consistent with our previous study . HoweverThe omission errors are an indicator of deficits in sustained attention in response to target stimuli. Our data showed that the G1287A polymorphism may affect the outcome of MPH treatment on sustained attention deficits in ADHD, with the G/G genotype being associated with the greatest MPH-induced decrease in omission errors. This result with MPH is consistent with the results reported by Yang et al. , which iDespite the possibility of a role of the G1287A polymorphism in treatment response, a previous association study found no evidence of a biased transmission of any of the alleles of the G1287A polymorphism in a sample of Korean ADHD probands . In addiThe commission errors are an indicator of deficits in response inhibition, which is considered to be the core deficit in ADHD ,34. Our SLC6A2 and the consequent decrease in transcriptional activity in ADHD subjects with the T allele at the -3081 polymorphism, as reported by Kim et al. [In previous studies, the frequency of the T allele at the A-3081T polymorphism was significantly higher in ADHD subjects than in controls ,16, and m et al. , may resm et al. ,34. Our m et al. -40. FurtSeveral limitations may have influenced the findings in this study. First, the sample size of the present study is relatively small for genotypic analysis, so the results cannot be applied to the general population and should be interpreted carefully. Second, although the levels of performance of CPT and the frequencies of the NET polymorphisms in this study are similar to those in previous reports, we did not compare the CPT performances and NET polymorphisms of ADHD subjects and controls. Third, our study assessed CPT only after short-term MPH treatment outcomes. The MPH-induced neuropsychological changes produced by 8 weeks of MPH therapy may not be the same as long-term MPH-related changes. Forth, MPH was administered with no control of adherence by investigators. Finally, only three of the patients had the minor allele of the G1287A polymorphism, and this prevented precise statistical results.This preliminary study provides evidence for the possible roles of the G1287A and A-3081T genotypes of SLC6A2 in MPH-induced improvement in attentional performance and supports the noradrenergic hypothesis of the pathophysiology of ADHD. Further studies using larger sample sizes, controls, and long-term MPH treatment in the study designs should help to elucidate treatment-related neuropsychological changes related to genetic polymorphisms.ADHD: Attention-deficit hyperactivity disorder; MPH: Methylphenidate; NET: Norpeinephrine transporter; SNP: Single nucleotide polymorphism; CPT: Continuous performance test; ADHD-RS: Attention-deficit hyperactivity disorder rating scale; COMT: Catecholamine-degrading enzymes like catecholamine-O-methyltransferase; MAO: Monoamine oxidase.None of the authors have any financial interest in the study, or any other conflict of interest.SCC designed the study. SCC, JWK, BNK, and YHY participated in data collection. SBH and SP analyzed the data. SP prepared the first draft of the report. SCC and MSS supervised the statistical analysis. SP, SBH, MHP, and HJY interpreted the results. SP wrote the final report with input from all the authors. All authors read and approved the final manuscript.


The fibromatoses are a group of benign fibroblastic proliferations that vary from benign to intermediate in biological behavior. This article will discuss imaging characteristics and patient demographics of the adult type superficial  and deep (musculoaponeurotic) fibromatoses. The imaging appearance of these lesions can be characteristic (particularly when using magnetic resonance imaging). Palmar fibromatosis demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis and extending along the subcutaneous tissues of the finger in parallel to the flexor tendons. T1 and T2-weighted signal intensity can vary from low (higher collagen) to intermediate (higher cellularity), similar to the other fibromatoses. Plantar fibromatosis manifests as superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. Linear tails of extension  along the aponeurosis are frequent. Extraabdominal and abdominal wall fibromatosis often appear as a heterogeneous lesion with low signal intensity bands on all pulse sequences and linear fascial extensions  with MR imaging. Mesenteric fibromatosis usually demonstrates a soft tissue density on CT with radiating strands projecting into the adjacent mesenteric fat. When imaging is combined with patient demographics, a diagnosis can frequently be obtained. The fibromatoses are a broad group of fibroblastic proliferations with a similar histologic appearance containing spindle-shaped myofibroblastic cells, dense deposits of intercellular collagen fibers, variable amounts of extracellular myxoid matrix, and compressed and elongated vessels . They va The superficial  fibromatoses arise from fascia or aponeuroses at palmar, plantar, penile (Peyronie disease), and knuckle pad locations. Of the superficial fibromatoses, palmar fibromatosis is the most common followed by plantar fibromatosis , 4. Palmar fibromatosis (Dupuytren disease) is the most common of the superficial fibromatosis, affecting 1%-2% of the general population and approximately 4% of the United States population –7. It wa The etiology of palmar fibromatosis is believed to be multifactorial, including components of trauma, microvascular injury, immunologic processes, and genetic factors. Patients are typically over 65 years of age and the process is rarely seen in children. Males are affected 3-4 times more often than females and the disease is more severe in men . Clinically, patients present with painless, subcutaneous nodules involving the palmar aspects of the fingers, usually the fourth and fifth digits , 11. The Surgical intervention remains the treatment of choice, typically a selective fasciotomy. The decision to undergo surgical excision is determined by both patient symptoms and the presence of flexion contracture greater than 20 degrees at the metacarpophalangeal (MCP) joint or greater than 30 degrees at the proximal interphalangeal (PIP) joint . A simpl Radiographs may be normal or demonstrate flexion (Dupuytren) contractures of the MCP and PIP joints . On ultrasonography, the subcutaneous nodules of palmar fibromatosis are generally hypoechoic, hypervascular, and superficial to the flexor tendons , 17. The Computed Tomography (CT) demonstrates isoattenuated to slightly hyperattenuated nodular areas of subcutaneous thickening. MR imaging (MR) demonstrates multiple nodular or band-like soft tissue masses arising from the proximal palmar aponeurosis to the flexor tendons . The nod Plantar fibromatosis (Ledderhose disease) (Morbus Ledderhose) occurs less frequently than the palmar lesion, with an incidence of 0.23% . In our  Although the lesion can occur in children , 22, inc Patients present with one or more subcutaneous nodules, which most frequently arise in the medial aspect of the plantar arch (78%) and can extend to the skin or deep structures of the foot. Nodules may be multiple in 33% of cases . Palmar  The treatment of plantar fibromatosis is often conservative and consists of footwear modifications aimed at relieving symptoms . Surgica Radiographs are frequently normal in patients with plantar fibromatosis. Lesion evaluation is most commonly performed with ultrasound and MRI. Sonographic imaging demonstrates a well-defined (64%) or poorly defined 36%) fusiform mass in the soft tissues adjacent to the plantar aponeurosis . Plantar6% fusifo CT images demonstrate a nonspecific soft tissue mass in the characteristic location with attenuation equal or higher than skeletal muscle . MR imaging may demonstrate well-defined or ill-defined superficial lesions along the deep plantar aponeurosis, which typically blend with the adjacent plantar musculature. With its superior soft tissue contrast, MR is the best modality to determine infiltration of the lesion into the surrounding tissues and therefore it is most helpful for preoperative planning. Lesions typically show heterogeneous signal (92%), which is isointense to hypointense to skeletal muscle on T1W (100%) and T2W (78%) sequences. If the lesion has increased cellularity and less collagen, the T2 signal is increased (22%) . The deg The deep fibromatoses are fibroblastic proliferations that arise within the deep soft tissues and are traditionally divided into extraabdominal, abdominal wall, and intraabdominal types. They demonstrate infiltrative growth and local recurrence but do not metastasize. Their biological behavior may be considered intermediate due to frequent local recurrence. Involvement of adjacent vital structures may lead to patient demise, particularly with neck and chest wall lesions. Recurrent extremity lesions may eventually require amputation for local control , 6. The  The overall incidence of desmoid type fibromatosis is two to four individuals per million each year , 32. Rel Synonyms for extraabdominal fibromatosis include musculoaponeurotic fibromatosis, extraabdominal desmoid, desmoid tumor, well-differentiated nonmetastasizing fibrosarcoma, and aggressive fibromatosis , 6. Extraabdominal fibromatosis is most common in patients between puberty and 40 years of age, with a peak incidence noted between the ages of 25 and 30 years. Less than 5% of patients are younger than 10 years of age , 35. While these lesions can occur almost anywhere in the body, they have a predilection for the upper torso including the upper arm (28%), chest wall/paraspinal 17%), and head/neck 10% to 23%). Other less common locations include the thigh (12%), knee (7%), buttock/hip 6%), and forearms (4%). Lesions in the head and neck often behave more aggressively and may surround the axillary vessels, trachea, and brachial plexus, limiting the extent of surgical resection [%. Other %, and fo7%, and h Although these tumors are usually solitary, synchronous multicentric lesions  are note Extraabdominal fibromatoses typically present as a slow growing, painless mass which can limit range of motion of a nearby joint and invade adjacent neurovascular structures. Decreased range of motion, neurologic symptoms, and pain are reported but are unusual at presentation. Lesions are typically between 5 and 10 cm in size . Extraab The treatment of extraabdominal desmoid is usually a wide-local excision as it has a high tendency to locally recur. Traditionally, positive surgical tumor margins upon resection have been reported to be associated with a higher local recurrence rate. However, more recent studies have suggested that positive versus negative microscopic margins do not make a difference in the overall local recurrence rate , 39. Adj The rate of local recurrence varies from 19% to 77% (average 40%) and is usually within two years of resection , 6.Radiographs usually appear normal, although there may be signs of a soft tissue mass such as the failure to visualize the radiolucent cleavage plane between the soft tissue and bone, structural changes of the adjacent bone such as scalloping, or rarely soft tissue calcification or ossification may be seen . Bone inScintigraphy with Technetium-99m pertechnetate (Tc-99 m) has been used as a tumor scanning agent for follow-up of extraabdominal fibromatosis. Focal tracer accumulation is noted on blood pool and delayed static images .Sonography of desmoid-type fibromatosis reveals a hypoechoic lesion –51. The On CT, extraabdominal fibromatosis appears as a nonspecific soft tissue mass. Unless outlined by fat, the margins of the lesion are poorly defined. The attenuation of these tumors is variable, and has been described as lower than, similar to, or higher than skeletal muscle. Lesions with a higher attenuation are noted to have significant collagen components. One author suggests that a high attenuation lesion which is hypoechoic on ultrasound is suggestive of a fibrous lesion . The lowMR is frequently the modality of choice to evaluate and stage extraabdominal fibromatosis. Extraabdominal desmoid is usually centered in an intermuscular location, often along the deep fascia; therefore, a thin rim of surrounding fat may be noted (split-fat sign). Lesions may be well defined (49% to 54%) or have irregular infiltrative margins 46% to 51%) . T1-weig% to 51% Three histopathological stages of desmoid tumor have been described. In the first stage, lesions are more cellular , with laThe morphology of these low-signal areas as prominent band-like regions Figures  is more Signal intensity on long TR sequences may have an implication on tumor recurrence, with a higher recurrence rate in lesions with high T2 signal . LesionsIn lesions undergoing radiation or drug therapy, MR surveillance has been used to assess response to treatment  with a pAlthough not routinely performed in most institutions, it has been reported that diffusion-weighted imaging may help differentiate desmoid tumors from malignant soft tissue tumors, with fibromatosis demonstrating a higher mean apparent diffusion coefficient (ADC) than malignant soft tissue tumors .Areas of low T2-weighted signal are not specific to fibromatosis and may be seen with other lesions. A differential diagnosis for soft tissue lesions with prominent areas of low-signal intensity on T1- and T2-weighted sequences includes desmoid type fibromatosis, densely calcified mass, pigmented villonodular synovitis (PVNS)/giant cell tumor of tendon sheath (GCTTS), elastofibroma, granular cell tumor, desmoplastic fibroblastoma, and malignant fibrous histiocytoma (MFH)/fibrosarcoma .FDG PET has been utilized to evaluated decreased metabolic activity of all types of deep fibromatosis during chemotherapy , 66. Des Abdominal wall fibromatosis is indistinguishable both grossly and histologically from extraabdominal fibromatosis and the relative frequency is similar. It is discussed separately because of its characteristic location and the tendency to occur in women of childbearing age  during or more frequently within the first year following a pregnancy and in women who use oral contraceptives . It is t Clinical presentation is typically palpation of a firm, slowly growing painless soft tissue mass. Endocrine factors are most highly implicated in this form of deep fibromatosis by the frequent occurrence of these tumors during or in the year following pregnancy. Estrogen receptors have been reported in 79% of these lesions  and they These lesions frequently recur locally. The rate of local recurrence is reported to be 15% to 30%, less frequent than extraabdominal desmoid (35% to 65%) , 77. SimThe radiologic features of abdominal wall desmoid, with all imaging modalities, are essentially identical to those of desmoid type fibromatosis in other locations. Involvement of the rectus abdominis muscle is most common Figures  and 10.  Intraabdominal fibromatosis  is a rare group of closely related deep fibromatoses that occur in the pelvis, mesentery, and retroperitoneum . Despite Pelvic fibromatosis occurs in the iliac fossa and lower pelvis. It presents as a slowly growing palpable mass asymptomatic or causing slight pain. It is often mistaken for an ovarian neoplasm. The lesion occurs most frequently in women 20 to 35 years of age . The small bowel mesentery Figures  is the m Pelvic fibromatosis shows a female predilection, whereas mesenteric desmoids demonstrate a slight male predilection (55%) . The age Intraabdominal fibromatosis demonstrates sporadic occurrence, but the incidence is increased in patients with familial adenomatous polyposis (FAP), trauma or hyperestrogenic states , 52, 83. The presenting clinical signs and symptoms of mesenteric fibromatosis are often related to the small bowel. Patients may complain of abdominal pain or a palpable abdominal mass or come to clinical attention because of complications such as gastrointestinal bleeding, small bowel obstruction, fistula formation, bowel perforation, or hydronephrosis , 85, 86. Treatment options include surgical excision, hormone therapy, nonsteroidal anti-inflammatory drugs, and cytotoxic chemotherapy, although the optimal treatment regimen is controversial . While sIntraabdominal fibromatosis may result in local mass effect with displacement of adjacent bowel loops on radiographs . SerosalMesenteric masses may be discovered incidentally when patients are being evaluated for complaints of abdominal pain or discomfort. The sonographic appearance of mesenteric fibromatosis is a solid, well-circumscribed mass of variable echotexture and homogeneity , 80, 83.Mesenteric fibromatosis usually demonstrates a soft tissue density with radiating strands projecting into the adjacent mesenteric fat Figures  and atteMost intraabdominal lesions are low or intermediate signal intensity on T1-weighted images and have heterogeneous low-, intermediate- or high-signal intensity on T2-weighted images. The relative amount of hyperintensity on T2-weighted images reflects the degree of high cellularity areas and myxoid stroma within the lesion. The intravenous contrast enhancement pattern of mesenteric fibromatosis with MR is variable. Lesions that do not significantly enhance with iodinated contrast material on CT scans have been shown to enhance with intravenous gadolinium on MR imaging , 86. In Mesenteric fibromatosis has been reported as a false positive during FDG PET for detection of metastatic disease , 92. Gardner syndrome is a variant of familial adenomatous polyposis (FAP) containing osteomas, thyroid cancer, epidermoid cysts, fibromas, sebaceous cysts, and desmoid tumors in addition to the colorectal adenomatous polyps . Gardner syndrome is usually diagnosed in adults 25 to 30 years of age  and is m Patients with Gardner syndrome may demonstrate intraabdominal, abdominal wall, or musculoaponeurotic fibromatosis . Of the  Although similar in imaging characteristics to the isolated lesions, intraabdominal fibromatosis and other desmoid tumors associated with Gardner syndrome tend to be smaller and multiple and occur in a younger patient population. The smaller size and younger patient population may be secondary to more frequent imaging and follow-up examinations performed in patients with Gardner syndrome. Complications secondary to desmoid tumor are the most common cause of death in patients with FAP who have undergone prophylactic colectomy (30.6%) . In summary, the deep and superficial fibromatoses vary from low- (higher collagen) to-intermediate (higher cellularity) T1 and T2-weighted signal intensity depending on lesion cellularity. Palmar fibromatosis may result in flexion (Dupuytren) contracture and plantar fibromatosis typically involves the medial cord of the plantar fascia and blends with the adjacent plantar musculature. A heterogeneous lesion (well-defined or ill-defined) with nonenhancing low-signal-intensity bands on all pulse sequences and linear fascial extensions  are highly suggestive of abdominal wall or extraabdominal desmoid . Mesente


Background: Prenatal exposure to methylmercury (MeHg) and polychlorinated biphenyls (PCBs) has been associated with impaired performance on attention tasks in previous studies, but the extent to which these cognitive deficits translate into behavioral problems in the classroom and attention deficit/hyperactivity disorder (ADHD) remains unknown. By contrast, lead (Pb) exposure in childhood has been associated with ADHD and disruptive behaviors in several studies.Objectives: In this study we examined the relation of developmental exposure to MeHg, PCBs, and Pb to behavioral problems at school age in Inuit children exposed through their traditional diet.n = 279; mean age = 11.3 years) was obtained from the child’s classroom teacher on the Teacher Report Form (TRF) from the Child Behavior Checklist, and the Disruptive Behavior Disorders Rating Scale (DBD).Methods: In a prospective longitudinal study conducted in the Canadian Arctic, exposure to contaminants was measured at birth and at school age. An assessment of child behavior  based on the DBD.Conclusions: To our knowledge, this study is the first to identify an association between prenatal MeHg and ADHD symptomatology in childhood and the first to replicate previously reported associations between low-level childhood Pb exposure and ADHD in a population exposed to Pb primarily from dietary sources. Organicl delays . In maril delays . HoweverPCBs are synthetic organochlorine compounds (OCs) known for their long persistence in the environment. Like other OCs, their production and use has been banned or restricted in most industrialized countries, and population exposure to these chemicals now arises mainly from the ingestion of contaminated food e.g., . SeveralPb exposure has also been associated with impaired performance on neuropsychological tasks assessing attention and inhibition . PrenataThe Inuit population in Nunavik  is exposed to MeHg and PCBs through consumption of marine mammals and fish , and is Participants. The participants were Inuit children from Nunavik, a region located north of the 55th parallel, about 1,500 km from Montréal. Most of the participants (n = 208) were initially recruited under the auspices of the Cord Blood Monitoring Program (1993–1998), which was designed to document prenatal exposure to a range of environmental contaminants and nutrients in newborns in Arctic Québec (n = 57) were originally recruited for the Environmental Contaminants and Child Development Study  from the Child Behavior Checklist  collected at birth for the Cord Blood Monitoring Program or Environmental Contaminants and Child Development Study were previously analyzed for concentrations of Hg, PCBs, Pb, polyunsaturated fatty acids, and selenium (Se) to indicate prenatal exposure. Child blood samples (20 mL) collected for the present study were analyzed for the same contaminants and nutrients to document current body burden. Contaminant and Se analyses were performed at the Centre de Toxicologie, Institut National de Santé Publique du Québec . Omega-3 fatty acid composition of plasma phospholipids was analyzed at the University of Guelph Lipid Analytical Laboratory . Detailed analytical procedures for cord and child blood samples are described in Supplemental Material, pp. 2–4 (http://dx.doi.org/10.1289/ehp.1204976).Confounding variables. The following potential confounding variables were considered based on prior studies of the effects of environmental contaminants and our knowledge of socioeconomic and demographic factors associated with child development in the Inuit population: a) child characteristics: age, sex, birth weight, duration of gestation, adoption status (yes/no), and breast-feeding status (yes/no); b) maternal and family characteristics: age of biological mother at delivery, parity of biological mother before child’s birth, maternal education (years), marital status (single vs. married/living with partner), socioeconomic status (SES) based on the summation of predefined scores given for parental occupation status  and education  seafood nutrients: docosahexaenoic acid (DHA) and Se concentrations in cord and child blood samples; and d) other prenatal exposures: maternal tobacco use (yes/no), binge drinking , and illicit drug use (yes/no) during pregnancy. When data on maternal substance use during pregnancy were available from previous assessments, the information obtained closest to delivery was used to optimize the accuracy of responses . Otherwise, information provided for the present study was used. Correlations between previous and current maternal reports of substance use during pregnancy were in the moderate-to-strong range (rΦ between 0.42–0.80), suggesting reasonably robust validity of maternal reports provided a full decade after delivery.Statistical analyses. Normality of distribution was inspected visually for each variable and checked for skewness . The following variables, which exhibited log-normal distributions, were log transformed: cord and child blood Hg, PCB congener 153, and Pb; cord Se; parity; and each of the TRF outcome variables. A dichotomized (median split) variable was created for child Se because its distribution was neither normal nor log-normal. The following variables with extreme values (> 3 SDs from the mean) were recoded to one point greater than the highest observed non-outlying value, as recommended by n = 2), child DHA (n = 1), child age (n = 7), duration of gestation (n = 1), residential crowding (n = 1), maternal education (n = 3), SES (n = 1), and Raven score (n = 1).a priori based on previous research on the effects of neurotoxicants in school-age children  to each TRF score was examined using multiple regression analysis. The relation between each of these exposures and each of the DBD-based diagnoses was examined using binary logistic regression analyses, in which the contaminant concentrations were divided into tertiles. Both sets of multivariate analyses included a set of potential confounding variables selected children : child achildren , SES ]. Using cord and current plasma PCB values unadjusted for lipid values also did not alter the results (data not shown). the TRF . Child bAssociations with disruptive behavior disorders based on the DBD. Results from logistic regression analyses relating cord Hg and child Pb to the DBD-based diagnoses are presented in http://dx.doi.org/10.1289/ehp.1204976)]. None of the other exposure variables significantly predicted any of the DBD-based diagnoses (data not shown).In this study we examined the relation of developmental exposure to MeHg, PCBs, and Pb to behavioral problems reported by teachers in school-age children. Prenatal exposure to MeHg was associated with greater attention problems and with a substantially increased risk of teacher-reported symptoms consistent with ADHD. Specifically, children with higher cord Hg concentrations were about four times more likely to be identified by their classroom teachers as exhibiting behaviors that characterize the inattentive type of ADHD, though estimates were somewhat imprecise. In contrast, postnatal Pb exposure was associated with greater externalizing problems and with symptoms consistent with the hyperactive-impulsive type of ADHD. PCB, prenatal Pb, and postnatal Hg exposures were not significantly associated with any of these behavioral outcomes, and none of these exposures were related to ODD and CD.This is, to our knowledge, the first study to identify associations between prenatal MeHg exposure and behaviors that provide the DSM-IV diagnostic criteria for ADHD. The evidence of an increased risk of attention deficit reported here is consistent with findings from neuropsychological assessments of children in the Faroe Islands and findings from an event-related potential (ERP) study we conducted on a subsample of the children in the current study. In the Faroese, where the mean cord blood Hg concentration was similar to that found in our study, prenatal MeHg exposure was associated with impaired performance on attention tasks at 7 and 14 years of age . A recenAssociations with ADHD-type behaviors were observed at cord blood Hg concentrations > 11.4 μg/L. Although such exposure levels are common among children from Nunavik, relatively few children from the general Canadian and U.S. populations are exposed to such high Hg levels e.g., . HoweverThe results reported here contrast with those of a large birth cohort study conducted in the Seychelles Islands in which prenatal exposure was not associated with impaired performance on cognitive tasks or with an increased risk of ADHD-type behaviors . MeHg exOur results relating to postnatal Pb exposure replicate those of several previous studies where childhood Pb exposure was associated with ADHD  cohort study, where prenatal exposure was associated with higher rates of teacher-reported ADHD-like behaviors . One facongeners , which mongeners .The strengths of this study include our ability to control for confounding by other contaminants present in seafood—specifically for confounding of the association between cord Hg and outcomes by child Pb, and for confounding of the association between child Pb and outcomes by cord Hg. Another innovative aspect of this study is that we assessed prenatal and childhood intake of nutrients and evaluated them as potential confounders in the neurotoxicant–behavior relationships. Among the limitations of this study is that the maternal report of substance use during pregnancy was obtained in many cases about a decade after delivery. We tried to minimize this limitation by using data obtained at 1 month or 5 years postpartum when available, although this was not possible for the entire sample. Another limitation is that we do not have formal diagnoses for ADHD, but rather ADHD classifications based on behavior ratings provided by the classroom teachers. Although the elementary school classroom is an optimal context for observing the behaviors that characterize ADHD, and teachers are in a unique position to compare these behaviors across children, clinical diagnoses of ADHD typically also incorporate observations from other sources, particularly parents. Finally, we were not able to control for family history of ADHD. Because ADHD was rarely recognized in the previous generation in Nunavik, this potential confounding factor could not be reliably assessed.To our knowledge, this study is the first to report an association between prenatal MeHg exposure and ADHD symptomatology at school age. The associations with teacher-reported ADHD symptoms observed in the current study suggest that adverse effects of prenatal MeHg on attention previously reported based on neuropsychological assessments may be clinically significant, and may interfere with learning and performance in the classroom. This study also suggests that prenatal MeHg exposure may be a risk factor for attention problems in diverse ethnic groups from Southern Canada and the United States who may be exposed to similar levels of MeHg through their diet. Although the main source of Pb exposure in our study population—lead shot  PDFClick here for additional data file.


The objective of this study was to examine the impact of co-occurring social and emotional difficulties on missed school days and healthcare utilization among children with attention deficit/hyperactivity disorder (ADHD).Data were from the 2007 U.S. National Health Interview Survey (NHIS) and were based on parental proxy responses to questions in the Sample Child Core, which includes questions on demographics, health, healthcare treatment, and social and emotional status as measured by questions about depression, anxiety, and phobias, as well as items from the brief version of the Strength and Difficulties Questionnaire (SDQ). Logistic regression was used to assess the association between co-occurring social and emotional difficulties with missed school days and healthcare utilization, adjusting for demographics.Of the 5896 children aged 6–17 years in the 2007 NHIS, 432 (7.3%) had ADHD, based on parental report. Children with ADHD and comorbid depression, anxiety, or phobias had significantly greater odds of experiencing > 2 weeks of missed school days, ≥ 6 visits to a healthcare provider (HCP), and ≥ 2 visits to the ER, compared with ADHD children without those comorbidities (OR range: 2.1 to 10.4). Significantly greater odds of missed school days, HCP visits, and ER visits were also experienced by children with ADHD who were worried, unhappy/depressed, or having emotional difficulties as assessed by the SDQ, compared with ADHD children without those difficulties (OR range: 2.2 to 4.4).In children with ADHD, the presence of social and emotional problems resulted in greater odds of missed school days and healthcare utilization. These findings should be viewed in light of the limited nature of the parent-report measures used to assess social and emotional problems. Attention-deficit/hyperactivity disorder (ADHD) is a common neuropsychiatric condition in children-5 with aSocial and emotional difficulties are particularly common and problematic in children with ADHD. Social difficulties present in a variety of forms and can lead to conflicts with family and problems with peers-21. EmotGiven the above data, it is important to understand the ways in which co-occurring conditions, including those characterized as social and emotional difficulties, can lead to various types of poor outcomes and functional impairment in children with ADHD, so that caregivers and providers can target interventions appropriately. In this study, we used data from the United States (U.S.) National Health Interview Survey (NHIS) to explore the association between social and emotional difficulties in children with ADHD and select outcomes. Available measures included both parent report of social and emotional difficulties (the brief version of the Strength and Difficulties Questionnaire [SDQ]) and parent report of physician-diagnosed depression, anxiety, and phobias. Unfortunately, teacher ratings and physician diagnoses were not available, and thus independent validation of parent reports was not possible. Available outcomes of interest included school days missed and emergency room (ER) and healthcare provider (HCP) visits over the past 12 months. We hypothesized that the presence of social and emotional difficulties in children with ADHD would be associated with increased school absenteeism and increased healthcare utilization, compared to ADHD children without these difficulties.The data were from a subset of the publicly available 2007 NHIS,34. The Data analyzed in the current study are from the Sample Child Core of the 2007 NHIS, which iADHD status was ascertained based on the parent reporting whether they had ever been told by a doctor or healthcare professional that their “child had Attention Deficit Hyperactivity Disorder (ADHD) or Attention Deficit Disorder (ADD).” The presence of depression, phobias, and anxiety, respectively, were defined based on the parent’s responses to the following 3 questions: “During the past 12 months, has a doctor or other health professional told you that your child had: (1) depression, (2) phobias or fears, (3) anxiety or stress?” For each child, an incremental internalizing burden index was computed by adding the number of internalizing problems  they experienced.Parental reports of their child’s social and emotional difficulties were also defined using items from the brief version SDQ,39. The Two questions were used to define HCP and ER visits in the preceding 12 months. Parents reported on the number of times the child had “seen a doctor or other healthcare professional about his/her health at a doctor’s office, a clinic, or some other place.” The responses were dichotomized into < 6 versus ≥ 6 visits . Parents also reported on the number of times the child had “visited a hospital emergency room (ER) about his/her health.” The responses were dichotomized into < 2 versus ≥ 2 visits to the ER . School attendance was based on parental reports on the number of days their child “missed from school because of illness or injury in the past 12 months.” The responses were dichotomized as having missed < 2 or ≥ 2 weeks  of school.The analyses for the current study included children aged 6–17 years whose adult proxy answered the ADHD diagnosis question in the NHIS 2007 survey. Children and adolescents less than 6 years of age (n=3284); those with mental retardation, developmental delay, or autism (n=230); and those who were missing the ADHD status variable (n=7) were excluded. The final sample included 5896 children and adolescents, including 432 with ADHD. The 5464 children and adolescents without ADHD were included in some of the secondary analyses.The primary analysis for this study was focused on the association between co-occurring social and emotional difficulties with missed school days and healthcare utilization among children with ADHD. To assess this association, logistic regression models with dichotomized outcomes  as dependent measures and comorbid condition  as independent measures adjusting for gender, age category , race, income, insurance status, and ADHD medication-use were employed.To give context to the primary analysis and determine if there was a differential association between comorbid conditions on missed school days and healthcare utilization by ADHD status, logistic regression models with outcome as the dependent measure and ADHD status, comorbid condition, and ADHD status-by-comorbid condition interaction as independent measures adjusting for gender, age category, race, income, and insurance status were utilized. Finally, descriptive statistics were used to characterize the ADHD and non-ADHD subsamples.All analyses were conducted in SAS version 9.1 , using procedures specifically designed to properly analyze complex survey data which employ sample weight, stratification, and cluster information. All percentages, means, and estimates were adjusted to account for the NHIS survey design. All statistical tests of differences in independent measures, including interactions, were conducted using a 2-sided significance level of 0.05.Of the 5896 children aged 6–17 years in the 2007 NHIS, 432 (7.3%) had ADHD based on parental reports. The majority of children with ADHD were male (69.7%), adolescent (65.9%), white (75.5%), insured (91.3%), and with a family income less than $75,000 per year (68.8%). Sixty-eight percent of these children with ADHD had been and/or were currently being treated with a prescription medication to treat difficulties with concentration, hyperactivity, or impulsivity. Approximately one-third of these ADHD children had comorbid anxiety, while comorbid depression (16.5%) and phobias (7.2%) were less common. Compared with a reported formal diagnosis, a higher percentage of parents reported that their ADHD child was unhappy or depressed (27.4%) or often seemed worried (47.3%). Similarly, about 40% reported their ADHD child got along better with adults than with children and did not have good attention, while about one-third reported their child had difficulties in emotions, concentration, behavior, or being able to get along with other people. Despite this data, over 90% of parents of ADHD children reported that their child was generally well behaved , compared with experiencing at least 2 ER visits (11%) and missing more than 2 weeks of school (8%). When assessing the impact of co-occurring social and emotional difficulties on school attendance and healthcare utilization, ADHD children with anxiety had significantly greater odds of missing more than 2 weeks of school , having at least 2 ER visits , and having at least 6 HCP visits , compared with those without anxiety. For ADHD children with depression, those with the comorbid condition were 10 times as likely as those without the comorbid condition to miss more than 2 weeks of school ; 7 times as likely to have at least 6 HCP visits ; and 3.5 times as likely to have at least 2 ER visits ]. Similarly, ADHD children with comorbid phobias were 10 times as likely to miss more than 2 weeks of school  as those without phobias, while being 3 times as likely to have at least 6 HCP visits  and 2 times as likely to have at least 2 ER visits . In addition, with each incremental increase in internalizing burden, ADHD children had significantly greater odds of missing at least 2 weeks of school , having at least 6 HCP visits , and having at least 2 ER visits .For the single, general SDQ item assessing difficulties in emotions, concentration, behavior, or being able to get along with other people (item 6), ADHD children with at least one of these complications experienced significantly greater odds of missing more than 2 weeks of school , experiencing at least 2 ER visits , and having at least 6 HCP visits , compared with those who did not have these difficulties.For the SDQ items associated with emotional difficulties (items 2 and 3), ADHD children who were worried had significantly higher odds of missing more than 2 weeks of school , experiencing at least 2 ER visits , and having at least 6 HCP visits , compared with those who were not worried. Likewise, ADHD children who were unhappy/depressed experienced significantly greater odds of missing more than 2 weeks of school , experiencing at least 2 ER visits , and having at least 6 HCP visits , compared with those who were not unhappy/depressed.For the SDQ items associated with social or behavioral symptoms of ADHD , children who did not have good attention were about 3 times as likely as children who did have good attention to miss more than 2 weeks of school  and 2.5 times as likely to have at least 2 ER visits , while experiencing at least 6 HCP visits was similar for those with and without good attention . As observed with good attention, ADHD children who were not well behaved had significantly higher odds of missing more than 2 weeks of school  and experiencing at least 2 ER visits , compared with those who were well behaved, while the odds for having at least 6 HCP visits were similar between those who were well behaved and who were not well behaved . ADHD children who got along better with adults experienced similar odds of missing more than 2 weeks of school , having at least 2 ER visits , and having at least 6 HCP visits , compared with those who did not get along better with adults.P=0.0490). Significant interactions were also observed for ADHD status and being well behaved (P=0.0060), as well as being worried (P=0.0420), for children experiencing at least 2 ER visits. ADHD children who were not well behaved had significantly greater odds of having at least 2 ER visits, compared with those who were well behaved , while non-ADHD children who were not well behaved had lower odds of having at least 2 visits to the ER, compared with non-ADHD children who were well behaved . On the other hand, both ADHD and non-ADHD children who worried experienced increased odds of having at least 2 ER visits; however, the comparison was significant for the ADHD cohort  and was not significant for the non-ADHD group .When assessing if there was a differential effect of comorbid condition on missed school days and healthcare utilization by ADHD status, three interactions were significant. As stated above, children with ADHD who got along better with adults had lower odds, although not significant, of missing more than 2 weeks of school compared with ADHD children who did not get along better with adults . Conversely, non-ADHD children who got along better with adults experienced significantly higher odds of missing more than 2 weeks of school , compared with those who did not get along better with adults. This diametric relationship resulted in a significant interaction effect  and emotional difficulties  and parent report of physician diagnosed affective disorders  can be used to identify children with significantly elevated rates of school absenteeism and ER and HCP utilization. Strikingly, a positive response on a single general item from the SDQ  identifies a subset of children 3 to 4 times as likely as peers answering negatively, to exhibit all three of the examined adverse outcomes. While this general association is compelling, consideration of the other independent measures provides additional insights. The remaining eight items examined can be organized according to the clinical/psychological domain to which they speak: Three to anxious symptoms ; two to mood ; and three to core ADHD symptoms or social behavior .In general, the presence of anxious symptoms had a more pronounced impact on school absenteeism than on ER or HCP utilization. While no further detail as to the nature of the anxiety was available, anxiety-related school avoidance is a well described phenomenon, and, in this regard, it is notable that of the three items, the strongest relationship with school absenteeism was observed for physician-diagnosed phobias (OR 10.4). It is also interesting that parent observation of “worry” (SDQ item 2) was as strongly predictive of increased absenteeism as was report of physician-diagnosed anxiety .Consistent with what has been observed in other studies, parent report of physician-diagnosed depression was associated with worse outcomes,41, and P=0.049). For non-ADHD children, those who got along better with adults tended to miss more school than those who did not; while amongst children with ADHD, those who got along better with adults tended to miss less school. One possible explanation for this finding is that, among children with ADHD, peer rejection is the norm[The impact of the remaining SDQ items on the outcomes of interest was mixed. A negative response on SDQ item 1  was actually the strongest predictor of multiple ER visits across all items, and the strongest among SDQ items of school absenteeism; in contrast, poor attention span (SDQ item 5) was more weakly associated with these outcomes. This result is consistent with the fact that children with predominantly inattentive forms of ADHD are more likely to exhibit more subtle problems  than their more declarative peers with hyperactivity. Finally, a child’s getting along “better with adults than with other children” (SDQ item 4) did not appear to be associated with any of the outcomes examined, perhaps because of the ambiguous nature of the question . This outcome is further reinforced by the significant interaction between ADHD status and this item in the models that predict school absenteeism  and to decreased healthcare utilization.ADD: Attention Deficit Disorder; ADHD: Attention-Deficit/Hyperactivity Disorder; CI: confidence interval; DSM-IV: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition; ER: Emergency room; HCP: Healthcare provider; NHIS: National Health Interview Survey; OR: Odds ratio; SDQ: Strength and Difficulties Questionnaire; U.S.: United States.PC, DM, SW, KS, and JJ are employees and shareholders of Eli Lilly and Company.PC was the principle scientist for this study. PC, DM, and JJ collaboratively wrote the first draft of the manuscript. All authors reviewed and edited subsequent drafts, and read and approved the final manuscript.


Bartonella henselae is a zoonotic, alpha Proteobacterium, historically associated with cat scratch disease (CSD), but more recently associated with persistent bacteremia, fever of unknown origin, arthritic and neurological disorders, and bacillary angiomatosis, and peliosis hepatis in immunocompromised patients. A family from the Netherlands contacted our laboratory requesting to be included in a research study (NCSU-IRB#1960), designed to characterize Bartonella spp. bacteremia in people with extensive arthropod or animal exposure. All four family members had been exposed to tick bites in Zeeland, southwestern Netherlands. The mother and son were exhibiting symptoms including fatigue, headaches, memory loss, disorientation, peripheral neuropathic pain, striae (son only), and loss of coordination, whereas the father and daughter were healthy.Bartonella exposure using B. vinsonii subsp. berkhoffii genotypes I-III, B. henselae and B. koehlerae indirect fluorescent antibody assays and for bacteremia using the BAPGM enrichment blood culture platform.Each family member was tested for serological evidence of Bartonella spp. antigens and bacteremia was confirmed by PCR amplification of B. henselae DNA from blood, and from a BAPGM blood agar plate subculture isolate. The son was not seroreactive to any Bartonella sp. antigen, but B. henselae DNA was amplified from several blood and serum samples, from BAPGM enrichment blood culture, and from a cutaneous striae biopsy. The father and daughter were seronegative to all Bartonella spp. antigens, and negative for Bartonella DNA amplification.The mother was seroreactive to multiple B. henselae bacteremia was not thought to occur in immunocompetent humans. To our knowledge, this study provides preliminary evidence supporting the possibility of persistent B. henselae bacteremia in immunocompetent persons from Europe. Cat or flea contact was considered an unlikely source of transmission and the mother, a physician, reported that clinical symptoms developed following tick exposure. To our knowledge, this is the first time that a B. henselae organism has been visualized in and amplified from a striae lesion. As the tick bites occurred three years prior to documentation of B. henselae bacteremia, the mode of transmission could not be determined.Historically, persistent  Bartonella are highly fastidious microorganisms that are difficult to document microbiologically in patient blood or tissue specimens [Bartonella sp. have been associated with persistent bacteremia in immunocompetent human patients experiencing a spectrum of symptoms and somewhat diverse disease pathologies [Bartonella sp. has also been associated with fever of unknown origin [Due to complex nutritional requirements and slow dividing times, which necessitate a prolonged incubation period for successful isolation, members of the genus pecimens . Over thhologies ,3. On a hologies . Infectin origin -9, and an origin -12.Bartonella spp. from animals and immunocompetent human patients, our laboratory developed a novel diagnostic platform based on biochemical optimization of a modified insect-cell culture liquid medium  [Bartonella DNA from the patient’s extracted blood and serum samples before, and after BAPGM enrichment culture and from isolates, if obtained, following subculture of pre-enriched samples onto blood agar plates. Research utilization of this testing platform has facilitated the documentation of B. henselae bacteremia in patients from the Australia [Bartonella spp. including Bartonella vinsonii subsp. berkhoffii genotypes I and II [Bartonella koehlerae[Candidatus Bartonella melophagi [Bartonella sp. related to Bartonella volans[Bartonella species and 16S-23S ITS strain type. In this study, four members of a family from the Netherlands were tested for serological, microbiological (isolation) or molecular (PCR amplification and DNA sequencing) evidence of Bartonella exposure or bacteremia, using five indirect fluorescent antibody assays and the Bartonella alpha Proteobacteria growth medium (BAPGM) enrichment culture platform, respectively. In addition, skin biopsies were obtained surgically from the son for BAPGM enrichment culture, histopathology, and laser confocal immunohistochemistry.In an effort to overcome limitations associated with the molecular detection and isolation of r BAPGM) . The BAPustralia , Englandustralia , and theustralia -12,15. II and II -12,15,16koehlerae,12,14,17elophagi , and a nla volans, from thla volans,11,13. SBartonella species by ticks [Bartonella sp. following tick bites. It was ultimately decided that the family would be tested in conjunction with an ongoing research study designed to determine the prevalence of bacteremia in people with animal and arthropod exposure. This research study was reviewed and approved by the North Carolina State University Institutional Review Board (NCSU IRB#1960) to assure conformity with all confidentiality and patient assurance laws in the United States. In July 2008, prior to the onset of illness in the mother and son, all four family members had experienced tick bites at the family vacation home in Zeeland, located in southwestern Netherlands, where they reported a large deer population. Tick attachments had also occurred during subsequent summer vacations. The family did not own a cat or dog, and all family members denied exposure to cats and cat fleas. During the three years prior to testing in the Intracellular Pathogens Research Laboratory (IPRL), the mother reported fatigue, headaches, memory loss, irritability, disorientation, chest pain, syncope (two episodes), fine tremors, shoulder pain, joint pain, loss of coordination, and peripheral neuropathic pain involving the arms. The son (an 18-year-old student) reported an illness of three-year duration, with symptoms including: fatigue, headaches, fine tremors, red conjunctivae, cervical lymphadenopathy, and striae involving both legs and the buttock. In the context of this manuscript, striae are irregular bands, stripes or lines in the skin. Between July 2009 and July 2011, both the mother and son underwent multiple diagnostic evaluations for infectious and non-infectious diseases. Both had been treated for a potential Borrelia sp. infection with multiple antibiotic combinations  for at least 6 weeks duration, on several occasions. The historical response to antibiotics was inconsistent and difficult to assess, but in general, symptoms would diminish while receiving antibiotics and reoccur weeks to months after antibiotic administration ended. The last date in which the mother and son took antibiotics was May 24, 2011 and July 7, 2011, respectively. The father (64-year-old investment banker) and daughter  were not symptomatic prior to or at the time of sample collection. As a physician, the mother decided that shipping samples from Europe to the United States might compromise sample integrity, thereby contributing to false negative test results. Therefore, after flying to North Carolina, the mother and son’s blood samples were aseptically collected during the last week of July 2011, whereas the father and daughter’s samples were collected the first week of August 2011. After the two week sample collection period, the family flew back to the Netherlands to await research testing results, which required months to complete. Three aseptically collected blood and serum samples were obtained during a one-week period from the mother, father, son and daughter. Three skin biopsy samples, which included a blue nevus located over the right deltoid, and a striae lesion  located on the left thigh, were surgically obtained from the son at a hospital in Raleigh, North Carolina, during the same time frame as blood samples were being collected. Blood, serum and skin biopsy samples were processed and tested in the IPRL, as described below. Histopathological examination of hematoxylin and eosin stained tissue sections was performed by the consulting human pathologist for the local hospital. Frozen tissues were sent to the Cutaneous Imaging Center, Department of Dermatology and Center for Drug Design, University of Minnesota to determine if Bartonella organisms could be visualized.While reviewing recently published literature relative to potential transmission of by ticks -24, the B. vinsonii subsp. berkhoffii genotypes I, II and III, B. henselae (strain Houston I), and B. koehlerae were determined using previously described indirect fluorescent antibody tests [Antibody seroreactivity to dy tests ,11,25.Bartonella sp. bacteremia. Briefly the procedure included inoculation of 2 ml of blood and up to 2 ml of serum collected the same day into a culture flask containing 10 ml of BAPGM. Cultures were incubated for up to 14 days at 36°C with 5% CO2 and 100% humidity with constant agitation. A milliliter of each enrichment culture sample was sub-inoculated onto blood agar plates  at 7 and 14 days after incubation of the BAPGM flask for potential colony formation. For each patient sample tested using the BAPGM platform, an un-inoculated BAPGM culture was processed in an identical and simultaneous manner to monitor for potential laboratory contamination .The BAPGM enrichment culture platform, which has been employed by several research laboratories -28 was uBartonella 16S-23S intergenic spacer (ITS) region was used to amplify Bartonella spp. DNA from extracted blood, serum, skin biopsies, BAPGM enrichment cultures and isolates [Using established assays, PCR targeting the isolates . All PCRBartonella henselae at a 1:100 dilution  plus donkey anti-mouse Cy5 at a 1:500 dilution (Jackson Immunoresearch). Washed samples were subsequently fixed to cover slips in agar, dehydrated in ethanol, cleared with methyl salicylate, and mounted in DEPEX .An excised skin biopsy sample from the son (striae lesion) was drop-fixed in formalin and stored at room temperature. As a negative control, a scalp skin 4-mm punch biopsy was drop-fixed in Zamboni’s fixative (0.03% (w/v) picric acid and 2% (w/v) paraformaldehyde) for 48 h at 4°C and then transferred to a 20% sucrose solution with 0.05% sodium azide in PBS for storage. Processing and multi-staining of tissues specimens was performed according to a previously published procedure ,30. VertB. henselae, B. koehlerae or B. vinsonii subsp. berkhoffii genotype I, II or III antigens by IFA testing (Table B. henselae (16S-23S SA2 strain type) DNA was amplified and successfully sequenced from his blood, serum, a BAPGM enrichment blood culture, and from the striae biopsy sample , B. koehlerae (1:64), and B. vinsonii subsp. berkhoffii genotypes II and III antigens (both 1:64), but was not seroreactive to B. vinsonii subsp. berkhoffii genotype I. Bartonella henselae SA2 bacteremia was confirmed in the mother by PCR amplification and DNA sequencing (460/460 bp homology with GenBank AF369529) of 16S-23S ITS PCR amplicons from an extracted blood sample and from colonies obtained on blood agar plates following BAPGM enrichment [B. henselae from the mother’s blood and amplification of B. henselae DNA after enrichment blood culture from the son supported active infection with viable intravascular bacteria. The father and daughter were not seroreactive to the Bartonella spp. test antigens used in this study and B. henselae DNA was not amplified from any of their blood, serum or BAPGM enrichment blood cultures. As detailed in previous studies [Bartonella DNA was not amplified from any of the simultaneously processed BAPGM negative culture controls (results not shown).The son was not seroreactive to ng Table . Howeverrichment ,11,18 fr studies ,11, BartB. henselae immuno-positive staining within the dermis and by confocal microscopy imaging, the bacteria were external to vascular tissue . During the final two months of antibiotic therapy, rifampin, hyperthermic therapy every day (sauna) and hyperbaric oxygen therapy by mask in a high-pressure cabin 2.4 bar, for 75 minutes each day were administered for 45 days. None of these therapies decreased the woman’s symptoms. As of March 2013, the father and daughter have remained healthy.After these results were obtained, the son elected to not be treated with additional antibiotics. During 2012 he remained mostly healthy, and passed Propedeuse exam Cum Laude. The striae regressed spontaneously leaving slight, colorless and painless marks. Conjunctivitis and the fine motor tremor have persisted. Psoriasis was diagnosed in 2012 for which he is being treated with vitamin supplementation and immune stimulants. The mother also did not seek treatment for B. henselae bacteremia was confirmed in the two symptomatic family members, but not in the two historically healthy family members. Although the symptoms that developed in 2008 as reported by the physician and her son were similar to questionnaire respondent symptoms reported by other patients with B. henselae bacteremia [. Unless re-infection was occurring, prior efforts to eliminate B. henselae with antibiotics were not successful, further supporting the possibility that antibiotic treatment failure can occur in a subset of B. henselae bacteremic patients [B. henselae bacteremia was confirmed, the purpose of this report was to provide evidence supporting B. henselae bacteremia in two immmunocompetent individuals from Europe, who believed that tick transmission was the most likely source of their infections. During the previous three years, all four family members reported tick bites while vacationing in southwestern Holland and all denied exposure to cats. As B. henselae DNA was successfully amplified and sequenced from one of the son’s BAPGM enrichment blood cultures and from a subculture isolate obtained from the mother’s blood, bacteremia (viable bacteria) was confirmed in both individuals despite prior administration of antibiotics. Only one of three blood culture sample sets from the mother and the son resulted in enrichment culture or isolation evidence to support the presence of bacteremia, which is consistent with prior experience with the BAPGM platform when testing sequentially-obtained blood samples from sick human patients [Bartonella spp. bacteremia in immunocompetent patients, and provides additional support for the need to test three sample sets obtained during a one week collection period [In this study, cteremia ,11, it ipatients ,31. As opatients ,17,19,32patients -36, as hpatients ,38 and rpatients ,39,40. Dpatients ,11,17. TB. henselae organisms in the son’s striae tissue biopsy. This observation provides preliminary evidence to support a potential association between B. henselae infection and striae. Although lay publications have frequently reported [Bartonella sp. infections, to our knowledge there are no scientific publications that have investigated, reported, or confirmed this possibility. Clearly, additional immunohistochemical studies of striae would be of interest to determine if persistent Bartonella sp. bacteremia could contribute to the development of these skin lesions in human patients.In addition to documentation of bacteremia, immunohistochemical confocal microscopy was used to visualize reported ,42 that B. henselae infection in immunocompetent people has been reported previously in the Netherlands in association with the diagnosis of typical or atypical cases of cat scratch disease (CSD) [B. henselae by cat fleas , develop a bacteremia that can persist for years [B. henselae or other Bartonella sp. infections is potentially detrimental for patient diagnosis and patient management decisions. Briefly, B. henselae, the acknowledged cause of CSD, has also been documented (by PCR or isolation) in dogs [B. henselae is the most frequent Bartonella species isolated from bacteremic sick dogs [B. henselae, bartonellosis was diagnosed following the bite (sting) of a bull ant (genus Myrmecia) [B. henselae infections as CSD is a contradiction in fact, and the use of the more globally applicable term such as bartonellosis is suggested. In addition, CSD is considered a self-limiting infection for which antibiotic therapy is not recommended, whereas more recent evidence indicates that antibiotic elimination of B. henselae bacteremia can be extremely challenging, and potentially difficult to achieve [B. henselae isolates based on 16S rDNA sequences and multiple-locus variable number tandem repeat analysis (MLVA), have documented the presence of two different B. henselae genotypes, one more frequently observed in association with human infections (genotype I), and the second (genotype II) most often isolated from bacteremic cats, suggesting that genotype II isolates may be minimally or nonpathogenic for humans (CSD) as compared with a more pathogenic and zoonotic genotype I [As is true throughout much of the world, se (CSD) ,44. Catsor years ,45-49. T in dogs ,25,50-54 in dogs ,56, fera in dogs , horses  in dogs -60, and  in dogs . In Nortick dogs ,11,62. Iyrmecia) . Those a achieve ,31. Intenotype I ,64.B. henselae DNA in ticks, including I. ricinus[Bartonella species. In addition, several recent publications have provided indirect [Bartonella spp.  by ticks (including I. ricinus) [Bartonella spp. DNA in ticks from the Netherlands [B. henselae SA2 strain DNA was amplified and sequenced from two I. ricinus ticks from Klasdorf, Brandenburg, Germany, by targeting the 16S-23S rRNA intergenic spacer region [B. henselae DNA sequences obtained from the two bacteremic people in this report. Interestingly, the remaining eight ticks that were sequenced as part of that study to confirm the Bartonella species and strain type contained a B. henselae 16S-23S Houston 1 DNA and were collected in southern Germany, France and Portugal, suggesting the possibility of B. henselae strain variation among ticks. It is also important to consider the tick life stage, as in that study the odds of detecting B. henselae DNA was 14 fold higher in nymphal ticks as compared to adult ticks [Bartonella sp. gene targets used to test tick DNA extractions can contribute to divergent findings among laboratories, when testing ticks from the same location. Most previous studies designed to detect and identify Bartonella species in I. ricinus ticks from Europe have targeted the citrate synthase (gltA) and 16S rRNA genes. Unfortunately, these genes have very limited genetic variability and therefore are not optimal to differentiate among B. henselae strains. Clearly the role of ticks as potential vectors for transmission of Bartonella sp. to animals and humans deserves additional research consideration.In recent years, a substantial number of European studies have reported the presence of . ricinus,65-76, sindirect ,23 or exindirect  to supporicinus) -24. Two herlands ,77, wherr region  (Kempf Vlt ticks . In addiB. henselae infection was documented by PCR amplification and DNA sequencing in both of the sick members of this family, there may or may not be a causal relationship between the bacteria and the reported symptoms. Bartonella serology was supportive of B. henselae infection in the mother, but not in the son, further supporting reports of seronegative Bartonella sp. bacteremia in human patients [Bartonella species in patient tissue specimens. Finally, as ticks removed from the patients were not saved for PCR testing, it is not clear whether infection with B. henselae was acquired by tick bites or by another mode of transmission.Although patients ,11,78,79Written informed consent was obtained from the patients for publication of this report and any accompanying images.Bartonella alpha proteobacteria growth medium; IPRL: Intracellular pathogens research laboratory.ITS: Intergenic spacer; BAPGM: Bartonella species infection in animals and human patients. Dr. Ricardo Maggi has led research efforts to optimize the BAPGM platform and is the Scientific Technical Advisor for Galaxy Diagnostics. All other authors have no potential conflicts.In conjunction with Dr. Sushama Sontakke and North Carolina State University, Dr. Breitschwerdt holds U.S. Patent No. 7,115,385; Media and Methods for cultivation of microorganisms, which was issued October 3, 2006. He is the chief scientific officer for Galaxy Diagnostics, a company that provides diagnostic testing for the detection of RM and PM performed the BAPGM enrichment blood culture and PCR testing of the patient samples, performed DNA sequencing and alignments, and generated the first draft of the manuscript. ME performed the immunohistochemistry and confocal microscopy. JB assisted in sample acquisition and serological testing. EB coordinated various aspects of the investigation and helped to draft the final manuscript. All authors read and approved the manuscript.


It is with great sadness that we note the sudden passing of our colleague and friend Professor Terje Sagvolden, a highly accomplished neuroscientist, well known across the world for his contribution to our understanding of the neurobiology of attention deficit hyperactivity disorder (ADHD). Here we pay tribute to this magnificent man and scientist in an intercontinental recognition of his contribution to science. Terje was a wonderful caring person, a kind considerate friend and a brilliant researcher. Terje was inspiring and creative, as well as a visionary. He pioneered collaborative research and forged links between basic and clinical researchers in different disciplines, across different countries.With Terje's help, the European Network for Hyperkinetic Disorders (Eunethydis), of which he was a founding member, obtained a major EU grant in 1993 that enabled the then participating centres to work on the same ADHD project cross-nationally. The effect of this was to harmonize research efforts in several European groups. This forged the basis for the later projects on genetics and intervention evaluation. In the discussions held at Eunethydis meetings, Terje took up the challenge with his characteristic enthusiasm to demonstrate that the animal model he was using had considerable clinical relevance to ADHD.Terje's seminal work was to demonstrate the relevance of the spontaneously hypertensive rat (SHR) for human ADHD. As Figure In 1998 there is the first major spike. This was primarily due to a special issue of Behavioural Brain Research that Terje edited with Joseph Sergeant and contained the particularly important contribution from the Naples group, led by Adolfo Sadile, who Terje met in 1980 in Erice, Sicily. They forged a partnership in the European Brain and Behaviour Society (EBBS) and Society for Neuroscience meetings. Terje became the secretary of EBBS and gave an enormous impulse to the growth of that society. At Eunethydis meetings, the Oslo and Naples groups developed fruitful novel questions, experimental approaches, and produced innovative results, which have been applied to human ADHD.Animal models in ADHD were something new in the 1980s, hence the challenge on their clinical relevance. By comparing ADHD traits between the SHR and the Wistar Kyoto (WKY) reference strain, Terje was able to establish unequivocally a genetic basis for ADHD traits in the SHR , the genIn the premature last phase of his research, Terje made another key discovery that will make lasting contributions to the genetics of ADHD. Although WKY rats had routinely been used as a reference strain without regard to source, Terje showed substantial behavioural and genetic differences in strains from different laboratories ,9. This Through his work within Eunethydis, he profoundly influenced the work of a younger generation of ADHD researchers, especially through his enthusiastic promotion of reinforcement and learning as an important focus for human ADHD research. This insight has played a seminal role in the fundamental shift in focus from cognitive to motivational models of ADHD that has occurred in the field. In that process of change, Terje took students and new colleagues under his wings and gave them the opportunity to take part in his own research and networks to form their own careers. Terje's ability to be always true to himself was a hallmark of his character.st IBRO school in Africa which was hosted by the University of the North in 2000, in Pietersburg, South Africa. Terje remained a faithful supporter of IBRO, particularly in African activities, organizing ADHD workshops and establishing an ADHD network in Africa.Africa would like to offer a special tribute to Terje. He was a great friend of the late Professor James Kamani and one of the founders of neuroscience in Africa. He played a significant role in the establishment of the Society of Neuroscientists of Africa (SONA) in 1993. Terje continued to support the promotion of neuroscience in Africa. He served on the International Advisory Committee of SONA and, together with Raj Kalaria, Michael Zigmond, Beth Fischer, Marina Bentivoglio, Anneke Meyer, and others, organized the 1Terje had very close links with the University of the North, which became the University of Limpopo in 2005. He held his first workshop there in 1997 and was instrumental in obtaining funds from theNorwegian Universities' Committee for Development Research and Education (NUFU), which kept the ADHD project in Limpopo going for 12 years. Under his guidance a very important epidemiological study was completed, involving six different ethnic groups. More cross-cultural neuropsychological projects followed. He was co-supervisor for a number of PhD students, who will sadly miss his expert guidance and warm encouragement. In 2008 he organised a week long workshop on scientific writing in Oslo for the PhD students from Limpopo. This was an unforgettable event as for most of them it was their first time to travel outside South Africa. He will be sadly missed at this institution as a co-worker, teacher, and mentor, but above all for his warm-hearted interest and friendship.Behavioral and Brain Functions in 2005). In 2005 he also established the Oslo ADHD Group, integrating basic studies of anatomy, neurophysiology, neuropsychology, genetics, and behaviour. The group presented their research at a symposium in Oslo in 2010, together with researchers from Canada, South Africa, the US and Europe. Terje believed in collaboration, openness and willingness to share one's knowledge, insights and ideas in order to move science forward.Terje's approach to research was collaborative and multidisciplinary. He facilitated several collaborative projects across the world. In the academic year 2004-2005, he led an international research group at the Centre for Advanced Studies at the Norwegian Academy for Science and Letters which for so many of us was a key catalyst in generating new ideas and new lines of research thus enhancing our international collaborations (as illustrated by joint publications and the establishment of Always innovative and creative, Terje played a major role in designing experiments for children that were directly analogous to the behavioural studies with animals. Through building a response apparatus that could be operated by children in much the same way as that for the rats, behavioural responses could be analyzed in the same way across species . UltimatThe list of contributions to the field of ADHD is impressive but fails to capture the passion with which he worked and interacted with his colleagues, who will sorely miss him Figure .


Attention Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder, being one of the most prevalent psychiatric disorders in childhood. The neural substrates associated with this condition, both from structural and functional perspectives, are not yet well established. Recent studies have highlighted the relevance of neuroimaging not only to provide a more solid understanding about the disorder but also for possible clinical support. The ADHD-200 Consortium organized the ADHD-200 global competition making publicly available, hundreds of structural magnetic resonance imaging (MRI) and functional MRI (fMRI) datasets of both ADHD patients and typically developing (TD) controls for research use. In the current study, we evaluate the predictive power of a set of three different feature extraction methods and 10 different pattern recognition methods. The features tested were regional homogeneity (ReHo), amplitude of low frequency fluctuations (ALFF), and independent components analysis maps . Our findings suggest that the combination ALFF+ReHo maps contain relevant information to discriminate ADHD patients from TD controls, but with limited accuracy. All classifiers provided almost the same performance in this case. In addition, the combination ALFF+ReHo+RSN was relevant in combined vs. inattentive ADHD classification, achieving a score accuracy of 67%. In this latter case, the performances of the classifiers were not equivalent and L2-regularized logistic regression  provided the most accurate predictions. The analysis of brain regions containing most discriminative information suggested that in both classifications (ADHD vs. TD controls and combined vs. inattentive), the relevant information is not confined only to a small set of regions but it is spatially distributed across the whole brain. Attention Deficit/Hyperactivity Disorder (ADHD) is a worldwide prevalent disorder  and functional MRI (fMRI) techniques have been extensively used in the quantitative analysis of the brain in healthy individuals and patients with psychiatric disorders in an attempt to increase our understanding of human brain structural and functional networks  to estimate the accuracy measures of classification (controls vs. ADHD and inattentive vs. combined ADHD) based on a large resting state fMRI dataset; (ii) to compare the prediction accuracy of different classifiers and/or penalty functions; (iii) to identify brain regions containing discriminant information between groups. The novel findings of this study are that most classifiers have approximately the same performance and that the discriminant information is not concentrated in a small set of regions but distributed in the entire brain.A diagram showing a summary of the analysis pipeline is presented in Figure The data used in the current study was acquired by the ADHD-200 Consortium which provided public release of 929 resting state scans of children and adolescents with ADHD and typical controls. The data was acquired in eight different sites: Peking University, Bradley Hospital/Brown University, Kennedy Krieger Institute, NeuroIMAGE Sample, New York University Child Study Center, Oregon Health & Science University, University of Pittsburgh, and Washington University. This data was released in the ADHD-200 Competition, coordinated by Prof. Damien Fair and Prof. Michael Milham, and organized by the Consortium. The competition released both the structural MRI and fMRI scans of 759 subjects with the respective labels  in order to motivate participants to train and develop algorithms to predict the group of a single subject, given his/her neuroimaging data. The data of additional 170 subjects was then released without the group labels and the competition participants were asked to send the predicted labels. The true label of this test set of subjects was then released after the announcement of the competition results. All research conducted by ADHD-200 contributing sites was conducted with local Internal Review Board approval, and contributed in compliance with local Internal Review Board protocols. All data distributed via the International Neuroimaging Data sharing Initiative is fully anonymized in compliance with the HIPAA Privacy Rules. Prior to release, it is ensured that the 18 patients’ identifiers were removed, as well as face information. The complete demographic data is presented in Table z-score. The absolute values of the z-scores were cut using a threshold value of three and summed across all intra-cranial voxels for a quality score for each image. This information is available at the linkThe preprocessing of the raw fMRI data was carried out by Cameron Craddockf < 0.08 Hz); spatial smoothing the filtered data using a Gaussian filter .The main focus of The Athena pipeline is a systematic and homogeneous processing of all resting state fMRI datasets, and consisted on the following steps: exclusion of the first four echo-planar (EPI) volumes; slice timing correction; deoblique dataset; correction for head motion (first volume as reference); masking the volumes to exclude voxels at non-brain regions; averaging the EPI volumes to obtain a mean functional image; co-registration of this mean image to the respective anatomic image of the subject; spatial transformation of functional data into template space (4 mm × 4 mm × 4 mm resolution); extraction of BOLD (blood oxygenation level dependent) time series from white matter (WM) and cerebrospinal-fluid (CSF) using masks obtained from segmenting the structural data; removing effects of WM, CSF, motion, and trend using linear multiple regression and holding the residuals; temporal band-pass filter  for new observations. Here, we evaluated three different types of features from functional brain imaging: ReHo, fALFF, and independent component analysis maps.The ReHo approach . Thus, it was necessary to apply a dimensionality reduction procedure in order to avoid numerical singularities (and in terms of computing time and optimization) and overfitting problems. Since neuroimaging data have a very high dimensionality, this step plays a crucial role in classification studies :AdaBoostM1 (AdaB);Bagging (Bagg);LogitBoost (LogB);L2-regularized L2-loss support vector classification dual (L2L2SVMd);L2-regularized L2-loss support vector classification primal (L2L2SVMp);L2-regularized L1-loss support vector classification dual (L2L1SVMd);L1-regularized L2-loss support vector classification (L1L2SVMd);L1-regularized logistic regression (L1logR);L2-regularized logistic regression dual (L2logRd);L2-regularized logistic regression (L2logR).The first three classifiers are available in Weka package for data miningThe AdaB  are based on logistic regression, linear SVM, sparse logistic regression, and sparse SVM. The basic idea of linear SVM is to find a linear boundary with maximum separation margin between the two groups to be classified , we have a set of k predictor variables in a vector j =x1,x2,…kx and the group of this subject is jy (specified by −1 or 1). The classifiers try to find the best set of coefficients in a vector Suppose for each subject L is called loss-function. Basically, the SVM, logistic regression and their variations (sparse solutions) differ on the specification of this function. The difference between primal and dual versions is not in the loss-function, but on the implementation of the optimization algorithm. A detailed explanation about each considered loss-functions and the optimization details can be found in Fan et al.  was calculated. In the following, the classifiers were then re-trained using the training data but removing one feature at a time from the feature set. Then, the predictions for the test data were obtained and the “feature-out accuracy” based on classifiers vote was calculated. The difference between the feature-out and global accuracy was then considered to be the measure of the relevance of each feature left-out in discriminating the two groups of interest. Discriminative brain maps were then built to depict the 5% most relevant features from this general evaluation. When two or more modalities of features  are being considered as predictors in the same classifier, the results are displayed in separate brain maps for each modality for visualization purposes.Boxplots showing the classifiers performance for controls vs. ADHD (features: ReHo+fALFF) and combined vs. inattentive ADHD (features: ReHo+fALFF+RSN4) predictions are presented in Figures In the case of controls vs. ADHD predictions, it was found that the ReHo and fALFF can separately see  and joinRegarding the results of combined vs. inattentive ADHD classification, the total score levels of all classifiers Figure  were conComplementary to the previous results, the scores of the classifiers trained with the entire training dataset of 759 subjects are presented in Table The discriminant regions for controls vs. ADHD classification and combined vs. inattentive are shown in Figures In the current study, we investigated the predictive accuracy of different machine learning and feature extraction algorithms for the classification of TD controls vs. ADHD patients and combined vs. inattentive ADHD. Our main concern was to compare the performance of the classifiers and also to evaluate the discriminant information contained in fALFF, ReHo, and RSN maps. We provided a systematic comparison of these methods using the ADHD-200 Consortium dataset released by the ADHD-200 competition (in September 2011).The first point to be discussed is that the scientific community had a fundamental role in the implementation of the current study. The ADHD-200 consortium provided a large multicenter neuroimaging database and excluding some few exceptions, current studies exploring the predictive power of the state-of-the-art classifiers and neuroimaging in clinical applications report findings from relatively small samples (tens of subjects). In addition, the community has benefited considerably from the work of the Neurobureau and several collaborators, which preprocessed the enormous amount of raw data. These contributions were crucial since they allowed the participation of researchers from outside of the neuroimaging community and were extremely helpful to the researchers from the community, facilitating the features extraction implementation. The Neurobureau and the collaborators who provided the scripts for image processing motivated an innovative and multi/interdisciplinary research during the ADHD-200 competition. As described previously, the RSN, ReHo, fALFF maps, and CC400 atlas, which had a pivotal role in this study, were obtained via Neurobureau. In addition, the classification routines were also obtained from the scientific community via libraries LiblineaR and RWeka from the R-project platform for Computational Statistics.The main findings of the current study can be summarized under two aspects: classifiers performance and identification of discriminative regions. The boxplots presented in Figure The classification between combined vs. inattentive ADHD Figure  seems tot-tests or GLM is the ability to identify and use spatially distributed subtle differences to make predictions, even in cases in which different modalities  are combined  of the samples are not fully matched and thus, may contain discriminative information for group’s prediction. On the other hand, we argue that it would be unrealistic  to have a complete homogeneous, controlled, and perfect matched samples, since it is already know that some demographic and behavioral data are indeed associated with ADHD. Actually, we also believe this is not a crucial point, so long as classification methods are not used as the main diagnostic reference but are used to provide complementary evidence and support. A second limitation to be mentioned is that we did not consider any brain region masking based on previous information from the literature. We chose to apply a more exploratory (whole brain) approach to investigate discriminant information in the data. However, the accuracy of the classifier could be higher if only the features from “The ADHD-200 completion is only the beginning of a new era of data and expertise sharing. Since the consortium has already released the complete data, we expect a big wave of studies using sophisticated data mining methods over the next few years. These studies will offer a detailed investigation of yet unexplored characteristics of neuroimaging data, which will play a crucial role to define more sensitive/specific features and also to develop new feature extraction methods. In this study, only three feature extraction methods were evaluated  but other approaches can also be applied to the same data. In addition, although most classifiers have shown approximately the same performance, the accuracy was more dependent on the features, highlighting how crucial is the choice of the predictor variables. Finally, we hope that the ADHD-200 competition has inaugurated a new paradigm in Neuroscience research, strongly founded on public data sharing and interdisciplinary collaborations.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.http://www.frontiersin.org/Systems_Neuroscience/10.3389/fnsys.2012.00068/abstractThe Supplementary Material for this article can be found online at