Attention-deficit/hyperactivity disorder (ADHD) is a neuropsychiatric condition that may be related to an imbalance of neural transmitters. The gut microbiota is the largest ecosystem in the human body, and the brain-gut axis theory proposes that the gut microbiome can affect brain function in multiple ways. The purpose of this study was to explore the gut microbiota in children with ADHD and assess the possible role of the gut microbiota in disease pathogenesis to open new avenues for ADHD treatment.A case-control design was used. We enrolled 17 children aged 6–12 years with ADHD who were treated in the Pediatric Outpatient Department of the First Medical Center of the Chinese PLA General Hospital from January to June, 2019. Seventeen children aged 6–12 years were selected as the healthy control (HC) group. Fecal samples of cases and controls were analyzed by shotgun metagenomics sequencing. Alpha diversity and the differences in the relative abundances of bacteria were compared between the two groups. Functional annotations were performed for the microbiota genes and metabolic pathways were analyzed using the Kyoto Encyclopedia of Genes and Genomes (KEGG).Faecalibacterium and Veillonellaceae were significantly reduced in children with ADHD (P < 0.05), Odoribacter and Enterococcus were significantly increased [linear discriminant analysis (LDA) > 2]. At the species level, Faecalibacterium prausnitzii, Lachnospiraceae bacterium, and Ruminococcus gnavus were significantly reduced in the ADHD group (P < 0.05), while Bacteroides caccae, Odoribacter splanchnicus, Paraprevotella xylaniphila, and Veillonella parvula were increased (P < 0.05). Metabolic pathway analysis revealed significant between-group differences in the metabolic pathways of neurotransmitters  (P < 0.05).There was no significant difference in the alpha diversity of gut microbiota between the ADHD and HC groups. Compared with HCs, Composition differences of gut microbiota in subjects with ADHD may contribute to brain-gut axis alterations and affect neurotransmitter levels, which could contribute to ADHD symptoms. Attention-deficit/hyperactivity disorder (ADHD) is a neuropsychiatric disorder that occurs most frequently in school-age children and is characterized as inattention with or without excessive impulsivity and hyperactivity . PreviouGut microbiota alterations may be associated with neurological conditions including Alzheimer’s disease, epilepsy, and autism . Many reWe conducted a case-control study to analyze differences in intestinal flora composition between children with ADHD and healthy control (HC) children, explore ADHD pathogenesis, and investigate potential new treatments for ADHD.2  (Seventeen children aged 6–12 (median 8 years) with ADHD were selected from the Pediatric Outpatient Department of the First Medical Center of the PLA General Hospital between January and June, 2019. The inclusion criteria were: (1) The Kiddie Schedule for Affective Disorders and Schizophrenia  was used to diagnosis ADHD, and subjects met the diagnostic criteria for ADHD in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5)  based onalities) ; and (6)The study was approved by the PLA General Hospital Ethics Committee (no. 2018-278). All subjects’ guardians were informed about the intentions of this study, and gave written informed consent was obtained in accordance with the Declaration of Helsinki.A total of 34 stool samples were collected from 17 ADHD patients and 17 age-matched HCs. We applied shotgun metagenomic sequencing to the whole genome of the microorganisms for each specimen. Bead beating was performed to rupture the bacteria, DNA was extracted with HiPure Stool DNA kits , and Qubit 4.0 software  was used for quality assessment. The library was prepared with a KAPA Hyper Prep Kit  and paired-end sequencing was performed on an Illumina NovaSeq platform  with a reading length of 150 bp (PE150).1 to screen out low-quality short frame sequences and chimeric sequences among the structural primer sequences (2.All genome sequencing data were preprocessed by KneadDataequences . Bowtie2equences  was thenHUMAnN2 (version v0.11.2) was used to analyze the species abundance, gene function, and metabolic pathways related to the processed sequencing data . HUMAnN23.To determine the gene functional annotations, we employed the Bowtie2 (version 2.3.4.3) to map the sequences after removing low-quality sequences and host sequences, to Integrated Gene Catalog databases and Kyoto Encyclopedia of Genes and Genomes (KEGG). On this basis, gene abundance and alpha diversity indexes were calculated, which involves using the Shannon, Chao1, and Simpson indexes to calculate the entropy values of gene abundance. Euclidean distance was also computed as the measurement of beta diversity, followed by principal component analysis (PCA) and permutational multivariate analysis of variance (PERMANOVA). PCA was performed using ade4 package and PERMANOVA was carried out using vegan package (R version 3.5.3)t-tests were used to compare age, BMI, and CPRS scores. Wilcoxon tests were used by SPSS 21.0 to assess differences in species abundance and gene function between the ADHD and HC groups. The LDA effect size (LEfSe) method was used to determine the most differentially abundant taxa at the genus and species levels between the two groups.Chi-square tests were performed by SPSS 21.0 to compare sex differences between the ADHD and HC groups, and independent-sample 2. The 17 HCs included 13 (76.5%) males and 4 (23.5%) females with a median age of 8  and a mean BMI of 15.9 ± 1.1 kg/m2. There was no significant difference in the distributions of sex, age, or BMI between the two groups (P > 0.05). More children in the ADHD group  developed symptoms of constipation than in the HC group . The total CPRS scores were significantly different between the ADHD and HC groups . There were no significant differences in the subscores for psychosomatic symptoms (0.56 ± 0.34 vs. 0.53 ± 0.41) or anxiety (0.42 ± 0.32 vs. 0.51 ± 0.35)  males and 3 (17.7%) females with a median age of 8  and a mean BMI of 16.1 ± 1.2 kg/mThe Shannon (9.67 ± 0.42 vs. 9.52 ± 0.25), Chao1 (61.5 ± 11.6 vs. 57.5 ± 9.8), and Simpson (0.89 ± 0.07 vs. 0.88 ± 0.06) indexes were calculated to assess the alpha diversity of fecal microbiota in the ADHD and HC groups. There were no significant differences in index values between the two groups . At the Faecalibacterium and Veillonellaceae were significantly reduced in the ADHD group, while Odoribacter was significantly higher  terms were used to annotate the genes. Wilcoxon tests showed 91 KOs that were significantly different between the two groups  into dopamine, however, peripheral dopamine cannot penetrate the BBB to enter the CNS, thus reducing the effectiveness of levodopa   and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS)  . Both ofopamine) . Previouopamine) . As abov(PANDAS) . Additio(PANDAS) . Odoriba studies  found thFinally, we performed KEGG analysis to determine the gene functional annotations and abnormalities in metabolic pathways, to verify the speculation of the role of gut microbiota in the pathogenesis of ADHD. Reduced dopamine levels in the CNS may contribute to ADHD pathogenesis. We identified differences in the dopaminergic synaptic pathways between the ADHD and HC groups; the gene encoding PP1 catalytic subunit was significantly upregulated, which was considered to increase synaptic sodium ion flux. Dopamine receptors are transmembrane sodium/chloride-dependent transporters that belong to the family of transporters of norepinephrine, 5-HT, and dopamine, and are referred to as neurotransmitter: sodium symporters (NSS) . ProlongThere are several limitations to this study. First, our sample size was relatively small. Second, we did not perform transplantation of intestinal flora to confirm that gut microbiota composition affects ADHD symptoms.In summary, our results demonstrate that gut microbiota alterations occur in children with ADHD, which may contribute to abnormal metabolism of neurotransmitters. We cautiously speculated that the abnormal intestinal flora might be one of contributing factors of ADHD, the underlying mechanism may be related to changes in microbial functions that affect the function of the neuroendocrine system, leading to reduced levels of 5-HT and dopamine in the CNS, and ultimately to ADHD. Further studies should be carried out to investigate the CNS levels of dopamine and 5-HT, and animal studies are needed for functional verification.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation, to any qualified researcher.The studies involving human participants were reviewed and approved by the PLA General Hospital Ethics Committee. Written informed consent to participate in this study was provided by the participants’ legal guardian/next of kin.LW and W-RG contributed equally to the manuscript. LW and GY contributed to the study conception and design. W-RG, SZ, Y-LS, BW, and LW organized the database. W-RG, Y-LS, SZ, LW, and GY performed the statistical analysis. W-RG, LW, and GY wrote the first draft of the manuscript. All authors wrote sections of the manuscript, contributed to the manuscript revision, and read and approved the submitted version.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.


The term Attention Deficit Hyperactivity Disorder (ADHD) has a long history of problems behind it. The origin of all these problems lies in the lack of agreement in the assessment procedures and evaluation instruments. The diagnosis is clinical and is determined by the observation and information provided by parents and teachers. So, this is highly subjective and leads to disparate results. Therefore, on the one hand the inaccuracy of the diagnosis of ADHD, which has been based on subjective criteria, together with the fact that hyperactivity is one of the main symptoms of this disorder, implies that several studies (with limitations) have been carried out to record objective measures of movement in subjects in at least the last ten years. In order to solve some of this derived problems and limitations of previous studies, a computer program has been developed to objectively record the amount of movement of subjects. The main objective of this study is threefold: first to register the amount of movement of both experimental group and control group, then to compare them with the movement registered by observers and finally to determine the validity of the software developed as a tool to support the diagnosis of ADHD. Results show that there are significant differences in the amount of objective movement between a clinical group of subjects with ADHD and a control group, obtaining a higher average of movement the experimental group. In addition, results also demonstrate that the developed software is a valid tool for the evaluation of movement that solves the limitations of previous studies. The proposed tool is developed from different aspects to give it a multidisciplinary character. The term Attention Deficit Hyperactivity Disorder (ADHD) is used by the American Psychiatric Association in the Diagnostic and Statistical Manual of Mental Disorders  to descrThe problems related to ADHD not only come from outside the scientific community, but have also spread within itself: multiple doubts in reference to etiology, prevalence, evaluation instruments and procedures, etc. The key to all these problems lies in the lack of agreement when considering diagnosis. Thus, in the absence of any biochemical, structural or genetic condition that unequivocally determines the existence of ADHD, the diagnosis is clinical, that is, based on the professional expertise of the doctor, and it is determined by the observation and information provided by parents and teachers . This isConsequently, the inaccuracy of the diagnosis of ADHD, based on subjective criteria , togetheThe present paper tries to fill the aforementioned shortcomings by using Microsoft Kinect V.2. This device is able to completely track and record 25 joints of six human bodies through an infrared system, without placing any type of sensor in the body of the subjects ,17,18,19For all the above, and trying to contribute to broaden the knowledge about the behaviour of subjects with ADHD, a computer program has been developed to objectively record the amount of movement of the subjects. Subsequently, study techniques workshops have been designed as an incentive used for attendance, both for subjects with a firm diagnosis of ADHD and for control subjects.The main objective of this study is to introduce a multidisciplinary tool developed for objective analysis of movement in subjects with ADHD. A computer program was developed to record the amount of movement of subjects. The validity of this software as a tool to support the diagnosis of ADHD has been carried out by comparing the amount of movement of the group diagnosed with ADHD and the control group, and it has also been compared with the movement registered by observers.This research involved 65 children, aged between 7 and 12 years old. The children were classified into two groups: experimental group and control group. The experimental group consisted of 32 children with a firm diagnosis of ADHD: 24 boys and 8 girls. In total, 24 of the 32 children had a diagnosis of ADHD with a combined presentation and 8 with a predominantly inattentive presentation, according to the DSM-V criteria. The age range of the participants of the experimental group was 7 to 12 years old (M = 9.75 and SD = 1.50).The control group consisted of 33 children from a standardized sample: 17 boys and 16 girls. The age range of the participants in the control group was 8 to 12 years old (M = 9.69 and SD = 1.50).The project was presented to the Ethical Committee for Clinical Research (CEIC) of the General University Hospital of Alicante (HGUA), obtaining its approval. From that moment onwards, informed consent to participate in the study was given to the parents of children diagnosed with ADHD by the Children’s Mental Health Unit (USMI).Once the procedure for the recruitment of the sample of the experimental group was started, a primary education school was contacted for the recruitment of the sample for the control group. The same number of boys and girls were randomly recruited as the experimental group.The first step for the organization of the study techniques workshops was to look for an only space, since the attendees (the sample) came from different educational centres. We searched for a classroom at the University of Alicante (UA) with writing pad chairs, because it would greatly facilitate the recording with the Kinect device.The different sessions of the workshops were organized by grouping children on age basis and ensuring that there were children from both the control group and the experimental group in the different workshops. Only between 4 and 6 people attended to each of the workshops, due to the limitations of the Kinect device (it can only detect and track 6 bodies).Families of children sent by the USMI that were on some type of medication, were invited to attend a new workshop to “review and expand” study techniques. Second to this workshop, they had to attend without having taken any medication. The families showed interest in collaborating, since all of them agreed, so that we could have all the subjects of the experimental group that has been prescribed some medication within two measurements of movements: with and without medication.Two Kinect devices were used in each workshop in order to ensure the capture of movement of the subjects and prevent any type of technological incident The classroom was arranged in such a way that the speakers never stood in front of the Kinect devices . Thus, tAn observer attended each workshop together with the subjects and the speakers. Her role was to take notes on the subjects’ behaviour so that, in addition to having the objective movements of the subjects, the appreciations of an independent observer would be registered. Two of the behaviours registered by the observer, along the lines of the diagnostic criteria of the DSM-V and the World Health Organization , were thADHD Movements was developed for the analysis of the movement of several subjects using Kinect. The version of Kinect for Windows allows developers to make their own programs using gestures and body movements in a wide variety of applications, for this reason it is considered an innovative interaction interface between people and computers, in addition to its simplicity in the acquisition of data [ADHD Movements detects the number of visible skeletons and, to allow the observer to know if the detection is correct, it shows each skeleton and each joint on the screen The computer application  of data . This apThe application numbers each skeleton (from 1 to 6) in order of detection and saves its location in the environment. In this way, if for any reason, a skeleton stops being detected , when it returns to its location, the application assigns it the same number.x, y, z) of the objects present in the scene. In the case of a human body, it obtains the coordinates of each of the 25 joints that it detects for each skeleton. Each joint is identified by its name and position and it is measured with three coordinates  where  define the position and (z) represents the distance to the sensor, according to the coordinate space shown in Data obtained by the Kinect sensor includes information of depth measures and, therefore, of the coordinates , moderate (0.51 ≤ d ≤ 0.80) and large effect size (d > 0.80).In order to analyse the movement registered by observers between the experimental group and the control group, as well as to analyse the difference in movement registered by observers between the experimental group with and without taking their prescribed medication, the Student’s by Cohen  was inclROC curves) have been used in addition to the t-test.In order to analyse the differences between averages of movement of the different joints recorded by Kinect within the experimental group with and without their prescribed medication, receiver operating characteristic curves .SPSS 24 and MedCalc 12 were used for the statistical analysis.Statistical packages left ankle joint, the subjects with a firm diagnosis of ADHD obtained a higher average in the movement of the joints analysed, than those in the control group. The differences found between the two groups are significant for 14 of the 17 joints . In addition, the differences found between the two groups are statistically significant in 14 of the 17 joints analysed.Results show that there were significant differences in the amount of objective movement between a clinical group of subjects with ADHD and a control group, obtaining a higher average of movement in the experimental group in all the analysed joints  may restrict the ability to detect significant differences between the groups. This limitation must be taken into account nevertheless minimized if we consider that other studies have presented a lower sample size ,47. In aBesides, related to the sample size is the fact that experimental group consisted of 24 subjects with a diagnosis of ADHD with a combined presentation and eight with a predominantly inattentive presentation, according to the DSM-V criteria. In this study we have only analysed hyperactivity as a core feature of ADHD ,8, togethand, hand tip, thumb and foot joints. On the other hand, the Kinect device detects and records the human body better in standing position and in the study the data has been captured in real education/learning situations, where the subjects are sitting. For this reason, it is possible that in certain positions of the subjects  occlusions have occurred. In these cases, the skeleton detection software of the device interpolates the positions of the undetected joints, being able to produce slight deviations between the real position of a joint and the interpolated position.Secondly, in this study the Kinect V.2 sensor was used to record the movement of subjects due to its simplicity and effectiveness . In addisquirm in seat the difference in averages is statistically significant.The results indicate that for the two registered movements, the highest average corresponds to the experimental group with respect to the control group, although only in the movement squirm in seat the difference of averages is significant, with a high magnitude (d = 0.80).In the same way, when comparing the movements registered by the observers between the experimental group with and without the medication, the highest average corresponds to the group without medication. Only in the movement leave their seat when comparing the experimental group with the control group, may be due to both the “novelty” of the teaching/learning situation (it was the first time they were in that classroom and with those speakers) or to the effect of the medication. However, the results of the comparison of the group with and without medication cannot be due to this reason, since the assistants already knew the speakers and the classroom of the study techniques workshop.The absence of significant differences in the movement In any case, in the absence of previous studies in which a register of this type of movements associated with the diagnostic criteria of DSM-V and WHO for ADHD in a teaching/learning situation, we cannot compare results.ADHD Movements) for the Microsoft Kinect V.2 device is valid to capture the movement of 17 joints of up to 6 subjects in a teaching/learning situation.The software developed (squirm more in their seat, than students without ADHD.Students with ADHD present more movement and squirm more in their seat than ADHD students with the prescribed medication.Students with a firm diagnosis of ADHD without the prescribed medication present more movement and head joint.ADHD students with and without taking their prescribed medication present a similar amount of movement in the Girls with ADHD present more movement than boys with ADHD.The above results lead to a series of conclusions:


The objective of this study was to evaluate concussion-like symptom reporting among uninjured adolescents with Attention-deficit/hyperactivity disorder (ADHD), stratified by several cooccurring conditions, and to examine the base rate and predictors of uninjured adolescents with ADHD meeting diagnostic criteria for the International Classification of Diseases, 10th Revision (ICD-10) post-concussional syndrome (PCS). Participants in this cross-sectional, observational study, were drawn from a cohort of 48,834 adolescent student athletes from Maine (ages 13–18) with no concussion in the past 6 months who completed a preseason, baseline testing program between 2009 and 2015. The final sample included 3,031 students with ADHD, 2,146 (70.8%) boys and 885 (29.2%) girls. They were 15.2 years old on average (SD = 1.3). Concussion-like symptom reporting was more common in girls than boys. Most students with ADHD reported one or more symptoms (69.3% of boys and 81.1% of girls). The presence of an additional, co-occurring condition or comorbidity was associated with increased symptom reporting. In the absence of a recent concussion, 28.8% percent of boys and 47.1% of girls with ADHD endorsed symptoms resembling an ICD-10 diagnosis of post-concussional syndrome (PCS). Adolescents with pre-existing conditions were even more likely to endorse symptoms that resembled PCS (28–47% of boys and 45–69% of girls). Prior treatment for a psychiatric condition was the strongest independent predictor for meeting PCS criteria in boys, followed by treatment for migraines and co-occurring learning disorder. For girls, the only independent predictor was prior treatment of a psychiatric condition. In uninjured adolescent student athletes, ADHD appears to mimic the post-concussion syndrome. Adolescents with ADHD commonly endorse concussion-like symptoms in the absence of a recent concussion. Demographic characteristics (sex) and the presence of co-occurring conditions are related to symptom reporting in adolescents with ADHD. Understanding factors associated with baseline symptom reporting, such as pre-existing ADHD, is important when evaluating youth who have persistent symptoms following concussion as well as making both return to school and return to athletics decisions. Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder, occurring in roughly 10% of children and adolescents . ChildreIt has been estimated that 33 million children worldwide sustain a concussion annually . In the Physicians and other health care providers use symptom questionnaires as part of their diagnostic evaluation, to monitor clinical recovery, and to inform return to activity decision making . A challFor clinicians treating adolescents with ADHD who sustain a concussion, understanding factors associated with baseline symptom reporting is important when determining recovery from the injury as well as making decisions regarding return to school and return to sports. The goal of this study was to examine symptom reporting among uninjured adolescents with ADHD using a statewide dataset of over 48,000 student athletes. We sought to extend prior work in this area by stratifying symptom reporting among youth with ADHD by the presence or absence of several potentially important co-occurring health conditions. We hypothesized that many adolescents with ADHD would report concussion-like symptoms in the absence of recent injury, and that demographic factors  and co-occurring health conditions  would be associated with greater baseline symptom reporting.M = 15.0, SD = 1.3 years), who completed baseline preseason testing with the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT®) ; (ii) they reported a history of treatment for epilepsy/seizures (n = 495) or meningitis (n = 201), or reported undergoing brain surgery (n = 102); or (iii) they completed the test in a language other than English (n = 814). Of the remaining 46,125 eligible adolescents , 3,031 self-reported having ADHD (6.6% of the eligible sample) and represent the final sample for this study. The adolescents with ADHD included 2,146 (70.8%) boys and 885 (29.2%) girls. They were 15.2 years old on average (SD = 1.3). Adolescents completed ImPACT® prior to participating in their first sport for that school year. Institutional review board approval to create and use this de-identified database was obtained from Colby College (primary) and from Spaulding Rehabilitation Hospital (secondary use).Participants in this multi-year, cross-sectional, descriptive study were drawn from a cohort of 48,834 adolescent student athletes from Maine, USA, between the ages of 13 and 18 (ImPACT®)  between A demographics and health history survey is embedded in ImPACT, a computerized neuropsychological screening battery designed for use in sport concussion programs . The heaThe Post-Concussion Symptom Scale , 19 is aWe dichotomized the Post-Concussion Symptom Scale based on the ICD-10 symptom criteria for PCS. Namely, to meet ICD-10 PCS criteria, participants must endorse at least one symptom in at least three of the following categories: cognitive, somatic, emotional, and insomnia. Assignment of the specific symptoms to the respective category is denoted with superscripts in Logistic regression was used to determine which covariates were associated with symptom reporting, using PCS-mild as the dichotomous outcome variable to maximize the ratio of participants with each outcome category to the number of covariates. Separate regressions were conducted for boys and girls. The following co-morbid conditions were included as covariates: learning disability (LD), prior special education services or having repeated a grade (Academic Problems), number of prior concussions (Prior Concussions), prior treatment for migraines, prior treatment for substance abuse, and prior treatment for a psychiatric condition. All covariates were entered in a single step for each model. Age was not included as a covariate because symptom reporting varies little across this narrow age range of adolescents .The percentages of student athletes with ADHD who endorsed individual symptoms, stratified by gender, pre-existing health conditions, and concussion history, are presented in Fisher's exact tests were conducted to compare rates of individual symptom endorsement between adolescents with ADHD and another pre-existing condition compared to those without the pre-existing condition see , 2. In bn = 941), the frequency of PCS-mild was 20.5% for boys and 34.1% for girls; the frequency of PCS-moderate was only 4.9% for boys and 8.4% for girls.A substantial proportion of boys (28.8%) and girls (47.1%) with ADHD endorsed a cluster of symptoms similar to ICD-10 symptom criteria for PCS-mild see , and 8.6p = 0.003) and were more likely to report having never sustained a prior concussion . Girls who were excluded had a similar rate of PCS-mild classification (41.5 vs. 48%) and a similar rate of having never sustained a prior concussion (80.8 vs. 85.5%) compared to girls included in the model.Six predictor variables (listed in p < 0.001) and well-calibrated . Measures of discrimination suggested modest prediction accuracy  = 0.62, p < 0.001, i.e., better than chance but poor for classifying individual cases). For girls, the logistic regression model was also statistically significant (p < 0.001) and well-calibrated (Hosmer and Lemeshow p = 0.55). Measures of discrimination again suggested modest prediction accuracy .For boys, the logistic regression model was statistically significant  reported greater symptoms. Moreover, a substantial proportion of adolescents with ADHD endorsed a combination of physical, emotional, cognitive, and sleep-related symptoms that resemble an ICD-10 diagnosis of PCS see . Boys wiPrior treatment for a psychiatric condition had the largest effect size with regard to symptom reporting among both boys and girls with ADHD. This was also the case when considering the broader population of adolescents, not just those with ADHD . The patThe results of this study have implications regarding the clinical care for youth with ADHD. In a recent survey, the vast majority of pediatric primary care providers reported they typically allow a patient to return to physical activity or sports when they are completely asymptomatic (87% of respondents) . Our resThe percentile ranks presented in This study has several limitations. First, ADHD status and all other health history variables were determined via adolescent self-report. We were not able to verify this information through parent corroboration or medical chart review. With that said, self-reported health history information may be the only source available for school-based preseason testing and rapid screening assessments in certain clinical situations. Moreover, a prior study illustrated that adolescents who undergo baseline testing twice, separated by an average of 2 years, are highly consistent in reporting a personal history of ADHD . Second,In conclusion, many student athletes with ADHD and no recent concussion, even those without any additional pre-existing conditions, report a cluster of symptoms on baseline assessment that resemble a mild version of the ICD-10 post-concussional syndrome. Thus, ADHD appears to “mimic” the post-concussional syndrome in many adolescents. This study adds to a growing literature highlighting that concussion-like symptoms are non-specific –29, and paul.berkner@colby.edu.The data analyzed in this study was obtained from the Maine Concussion Management Initiative. Requests to access these datasets should be directed to Dr. Paul Berkner, The studies involving human participants were reviewed and approved by Colby College Institutional Review Board (IRB). Written informed consent from the participants' legal guardian/next of kin was not required to participate in this study in accordance with the national legislation and the institutional requirements.NC, NS, and GI contributed conception and design of the study. BM organized the database. NC and RS performed the statistical analysis. NC wrote the first draft of the manuscript. RS and GI wrote sections of the manuscript. All authors contributed to manuscript revision, read and approved the submitted version.GI serves as a scientific advisor for BioDirection, Inc., Sway Operations, LLC, and Highmark, Inc. He has received research funding from several test publishing companies, including ImPACT Applications, Inc., CNS Vital Signs, and Psychological Assessment Resources . He has received research funding as a principal investigator from the National Football League, and salary support as a collaborator from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. RZ has received salary support from the Harvard Integrated Program to Protect and Improve the Health of National Football League Players Association Members. RZ serves on the Scientific Advisory Board of Myomo, Oxeia Pharma, and ElMInda. The remaining 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.


Despite a multitude of research on executive functions and attachment in Attention Deficit Hyperactivity Disorder (ADHD), a synthetic approach to the matter seems to have been lacking. In this review, we attempt to check the available data against two hypotheses: (1) executive functions and attachment influence ADHD symptoms independently; (2) executive functions and attachment interact to produce ADHD symptoms. We found no evidence falsifying the former hypothesis and some evidence to refute the latter. Limitations of current study approaches and suggestions for further research are discussed. Specifically, we propose an attachment representation, rather than attachment style, approach to measuring the mediation thereof between executive dysfunctions and ADHD. Attention Deficit Hyperactivity Disorder (ADHD) is a psychiatric condition that contains a cognitive deficit (attention disorder) in its name. It is therefore no wonder that it has been investigated profusely by neuropsychologists whose main interest so far has been into the executive functions (EFs). EFs are understood as the capacity to act intentionally under the influence of dynamic feedback from the environment. The most typical aspects of EFs include: cognitive inhibition, cognitive elasticity, planning and working memory. Neuropsychologists seem to be in agreement that cognitive inhibition is the most prominent EF deficit in ADHD. Pointing to that are data from children ,2,3 and From a different perspective, researchers in the field of attachment theory  have estIt is not clear whether the neuropsychological and the attachment perspectives are looking at two sides of the same coin or at two different coins altogether. In other words, do EF and attachment styles interact to give rise to ADHD symptoms or do they account for different aspects of ADHD?ADHD was first conceptualized as a “hyperkinetic disease of infancy”. Emphasis was put on a “remarkable motor activity” and resulting problems, such as school disobedience. Attention difficulties, although noticed, were not seen as the main problem area . This chWhat followed was a multitude of psychological research on ADHD children trying to explain the symptoms of ADHD in terms of cognitive deficits. Meta-analytical studies confirmed that ADHD children perform worse on measures of attention, but also on measures of working memory, inhibition and planning; the latter three grouped together under an umbrella term of executive functions. Impaired inhibition was shown to be characteristic of ADHD children, as compared to typically developing and ones with reading disabilities .As the presence of EF impairment in ADHD children seems to have been well established, current research has shifted to questions about the relationship between executive dysfunctions and ADHD symptoms of inattention and hyperactivity.One line of thought is that attention problems and executive dysfunctions share a common underlying factor. It has been suggested that poor performance on both types of cognitive tests is due to an increased intra-subject variability in reaction times (ISV) . In otheAnother line of thought posits that executive functions and attention should be seen as parts of a more complex system of automatic vs. controlled processes . AutomatBoth lines seem to acknowledge that there may be other, possibly unconscious, factors influencing both attentional and executive performance. Whether they are due to interferences from other systems or to delayed automatization or both is yet unclear. However, there seems to be little discussion about what these factors could be. Some researchers directed their efforts to investigate the relationship between executive functions and attachment in ADHD. Attachment is a likely candidate as it can be described as a set of representations that, on one hand, can influence attentional and executive control, and on the other, is itself an automatic process that needs to be learnt and then modifies behavior without conscious supervision. Their results will be the main focus of this review.Attachment researchers seem to agree with the concept of critical periods in the development of EF. Fonagy and Target  claim thA securely attached child is able to take advantage of parental scaffolding . MaternaGene–environment interaction is especially important for children with ADHD as they are the ones who often did not experience adequate care in the critical periods. Evidence shows that children who experienced pathogenic care in the first years of life show more ADHD symptoms than the general population . AdditioOn the other hand, a significant proportion of ADHD children did not experience early deprivation. A comparison of adopted (A-) and not adopted (nA-) children with (-ADHD) and without ADHD (-nADHD) showed that A-ADHD children were the most impaired on EF, followed by nA-ADHD and finally A-nADHD children were the least impaired or not at all . In thisAttachment theory, conceived by Bowlby and operationalized by Ainsworth, posits that a child forms a specific bond with the caregiver in the first years of life. Through that bond, they internalize different kinds of symbols, memories and scripts (or predictable responses to own behavior) that influence later relationships. These internalizations are called internal working models (IWMs). The attachment system is formed within the interval of 6 months and 3 years. Once formed, the pattern of attachment (or attachment style) is rather stable; however, future long-term, close relationships can influence it.Distributions of attachment styles in typically developing (TDC) and ADHD children are presented in TDC are mostly securely attached, whereas ADHD children are mostly insecurely attached. Additionally, one-third of ADHD children have a disorganized attachment style, whereas only 6.3% of TDC do.Despite ample research on EF and attachment in ADHD children, we did not find any work that would directly discuss the influence of both variables on ADHD symptoms. So far we have concluded that the possibility of an indirect influence of EFs on ADHD through another variable (such as attachment) is highly likely. Therefore, the goal of this review is to check the database against two hypotheses. Hypothesis 1 (H1): EFs and attachment influence ADHD symptoms independently. Hypothesis 2 (H2): ADHD symptoms are product of a mediation between EFs and attachment.We searched the following databases: ProQuest, PubMed, Medline, Wiley, Science Direct, and Scopus. The following search formula was applied: (ADHD OR attention deficit disorder OR attention deficit hyperactivity disorder) AND attention AND (executive functions) AND attachment. The results were limited to peer-reviewed articles in English. We obtained over 5000 results.At least one research sample underwent some form of ADHD symptom evaluation.At least one aspect of EFs was evaluated.At least one aspect of attachment was evaluated .The following inclusion criteria were applied:Research sample consisted of adults.One exclusion criterion was applied:Finally, we included 8 articles in the analysis see .We set out to find evidence against both our hypotheses. As our hypotheses were effectively ones about a mediator effect of attachment/EF on ADHD symptoms or lack thereof, we applied criteria for a mediator effect of a variable  to set uHypothesis 1 (H1).A study proved that EF and attachment do not influence ADHD symptoms independently, if: (a) lack of influence of both variables on ADHD symptoms was demonstrated; (b) influence of any of the two variables was demonstrated but rendered insignificant after inclusion of the other as a covariate or after inclusion of the interaction effect into the model.Hypothesis 2 (H2).A study proved that EF and attachment do not influence ADHD symptoms through mediation, if: (a) lack of influence of any of the two independent variables was demonstrated; (b) influence of any of the two variables was demonstrated and one of the following: (1) lack of influence of putative mediator on putative predictor was demonstrated or (2) effect of predictor on ADHD symptoms remained significant after inclusion of predictor-mediator interaction.The results of the analysis are presented in Mean = 7.07; Standard Deviation = 1.93) was lower than the one of the other samples , although the difference was not statistically significant—p > 0.1. In H2-refuting papers, different measures of attachment and similar measures of EF were applied. Research 4 and 5 refuted H2 as it failed to demonstrate the influence of attachment on ADHD symptoms. Research 3 found the influence, but failed to demonstrate a relationship between EFs and attachment. Research 2 found the influence of EFs and attachment on ADHD symptoms as well as a relationship between the predictor and the mediator but the inclusion of the interaction term failed to rid the dependent variables of statistical significance.Research refuting H2 was conducted by independent teams. Mean age of the samples falsifying H2 (All papers found a relationship between EFs and ADHD symptoms. Six papers found a relationship between attachment and ADHD symptoms.Papers 5 and 6 found a relationship between EFs and both dimensions of ADHD (inattention and impulsiveness/hyperactivity). Paper 6 found an influence of EF and attachment on inattention but only an influence of EF on impulsiveness/hyperactivity.None of the papers reported a confounding effect of an external variable on EF. Paper 1 reported a confounding effect of early externalizing behaviors on the effect of attachment on ADHD symptoms. Paper 3 reported a confounding effect of general negativity on the effect of attachment on ADHD symptoms.The conclusion of our analysis is that no existing evidence allows to refute the hypothesis that EFs and attachment influence ADHD symptoms independently. In fact, zero out of eight papers falsified this hypothesis.Additionally, zero out of eight papers denied the direct influence of EFs on ADHD symptoms. Conversely, the direct influence of attachment on ADHD symptoms finds less support as four out of eight papers failed to demonstrate that such relationship exists.To further elaborate on that last sentence, it was observed that stimulant medication increased the number of ADHD children categorized as securely attached . The phaFuture research should investigate which aspects of ADHD are explained by EF deficits and which by attachment insecurity. It should also acknowledge the differentiated influence on parent/teacher-reported ADHD symptoms. Lastly, the current state of research warrants a need for an attachment evaluation that is better fitted to the ADHD population.The analysis proved the mediator hypothesis to be wrong, at least with the younger ADHD afflicted children. In total, 50% (four out of eight) of the papers excluded the possibility of a mediation. Out of the remaining four, one explained the influence of attachment on ADHD symptoms away by accounting for earlier externalizing behaviors and three did not include the interaction term in their models. This result calls for a modification of the original hypothesis.A possible reason for the observed lack of influence of attachment on ADHD symptoms may be due to its assessment as a trait. A different approach would assume that on-line attachment representations, rather than attachment style, influence EFs and only then do EF deficits produce ADHD symptoms. By on-line attachment representations we mean attachment representations that interfere with cognitive task performance. Such interferences must be inhibited in order to accomplish a cognitive task. Insecure attachment representations generate anxiety and make more demands on cognitive inhibition resources. In consequence, EFs are reallocated to attachment representation inhibition which results in lower EF test scores. What follows is what we believe to be premises for this line of thought.The first premise is the recent discovery that the apparent differences on EFs and sustained attention tests between ADHD and TDC are greatly reduced if intra-subject variability in reaction time (ISV) is taken into account . SecondlIt is worth noting that research on children not diagnosed with ADHD yielded a mediator effect of planning between disorganized attachment and attention problems and a mediator effect of sustained attention between disorganized attachment and social problems .This paper reviewed research on influences of EF deficits and attachment on ADHD symptoms. Research was analyzed against its power refute any of two hypotheses: H1: EFs and attachment influence ADHD symptoms independently; H2: ADHD symptoms are a product of a mediation between EFs and attachment. No evidence was found to refute H1; some evidence was found to refute H2. We encountered several methodological problems: validity of standard attachment measures in the ADHD population; assumption that attachment influences ADHD as a trait; concentration on EF test scores without including the confounding effects of intra-subject variability, and paucity of research.


Hong-Ou-Mandel (HOM) effect is known to be one of the main phenomena in quantum optics. It is believed that the effect occurs when two identical single-photon waves enter a 1:1 beam splitter, one in each input port. When the photons are identical, they will extinguish each other. In this work, it is shown that these fundamental provisions of the HOM interference may not always be fulfilled. One of the main elements of the HOM interferometer is the beam splitter, which has its own coefficients of reflection  HOM interference shows up in many instances, both in fundamental studies of quantum mechanics and in practical implementations of quantum technologies8. For example, one of the main practical applications of the HOM effect is to check the degree of indistinguishability of two incoming photons. When the HOM dip reaches all the way down to zero coincident counts, the incoming photons are perfectly indistinguishable, whereas if there is no dip, the photons are distinguishable. A HOM interferometer scheme was presented in1, one of the main elements of which was a beam splitter (BS). To observe quantum interference, a BS is chosen close to 1:1 (having coefficients of reflection R and transmission T close to 1/2). A theoretical explanation of the HOM effect based on constant coefficients R and T and boson statistics of photons is quite simple10. In this interpretation, we are not interested in what happens to the incident photons in the BS. For this, they consider BS lossless (hereinafter simply BS) as ideal, i.e. with constant coefficients R and T and BS is the source of the other two photons obeying bosonic statistics. In this case, the annihilation operators before entering 1 and 2 photons in BS represent 12)17) of the experimentally observed value P (P is the joint probability of detecting photons after exiting the BS on the output ports), the frequency distribution does not affect BS matrix R and T are constant values. Currently, the well-known HOM effect theories are based on calculating the value of P within the constant values of The HOM effect was first experimentallydemonstrated by Hong et al in 1987R and T are variables, which significantly affects the theory of the HOM effect. The problem of interaction of two photons in BS is solved analytically, allowing the determination of the photon statistics after exiting the BS. Within the general form R and T are some functions that depend on the frequencies of incident photons, the interaction time of two photons in BS, and on the BS material. This leads to the value of the coincidence counting probability P being calculated to take into account the dependence on the frequencies of R and T. It is shown that even in the case of identical incident photons and their average values P may not be observed, despite being predicted by the HOM interference theory taking into account the constants R and T. Indeed, in the case of constant coefficients, as well as without a time delay between two photons, i.e. 13. In our case, R and T can be considered constant, and the results obtained pass into well-known approaches. The theory developed here is especially important when planning experiments in the HOM interferometer and analyzing them; because the fluctuations of R and T can be very large, the results of such experiments may not be correctly interpreted.In the work presented the coefficients mentclass2pt{minim10. Thus, we will proceed from the fact that we have two ports at the input. Two input and output ports can be in the form of freely spreading photons or in the form of waveguides along which photons propagate. If the waveguides are connected, then we get BS in the form of a coupled waveguide. It should be added that such systems are usually studied using various simplified models, for example, Bose–Hubbar model18, Jaynes–Cummings model (JCM)19, Dicke model20 and others. We will try to approach this problem based on a complete record of the Schrödinger equation of all interacting particles in the system under consideration.It is well known that in quantum optics two modes of the electromagnetic field (two input ports) are usually considered, since even if 1 port remains unused, it should be considered as an input for vacuum fluctuations10, then the Hamiltonian of such a system will be ; a ; a; i photon acting on the electron with number a 10; and the sum 23), going from the operators q10. As a result, the Hamiltonian of Eq. , it is more convenient to consider not the electric field operators, but the photon creation and annihilation operators before entering BS  interacting with two photons. We represent the electromagnetic field of photons through the transverse vector potential entclass1pt{minimaentclass1pt{minimaentclass1pt{minimaore Eq. 2, going f14)26).The next problem, we consider is the probability 14), the only difference being that it is necessary to consider the T and R functions depending on the frequencies. As a result, we obtainT and R are assumed to be independent of frequencies and 29. It is also seen that the time delay of Equation  is appliT and reflection R, which leads to a nonzero value of We next consider the case of identical photons at mentclasspt{minimaned Eqs.  and 12)\document30. The second case, on the other hand, if we consider 30). Indeed, in this case, in Eq. (T(y) and R(y) are determined by the Eq. \documententclass1pt{minima31 (in this work v is wave velocity in a waveguide). In this case, the frequency dependence of the coefficients R and T disappears and it is always possible to experimentally select 31)If we assume that photons are completely identical and monochromatic to 0 in Eq.  , but fluctuations of the coefficients R and T are not studied. We should also add about the observation in the experiment of the studied effect of fluctuations. If the fluctuations are significant, then the visibility of It should be added that experiments do not always have good coincidences of T and the refraction of R depend on the frequency. This dependence can significantly change the well-known theory of HOM interference. Under certain conditions, when the dependence on frequencies can be neglected . This leads to the important conclusion that visibility T and R cannot be used to judge quantum interference, and for T and R during the experiment. In the case of HOM interference, the coefficients Thus, the developed theory shows that for a real BS, the coefficients of transmission case Eq.  for \doc2 in Eq. , where Tfrom Eq.  for \docV). With such an estimate, it is easy to obtain that T and R on frequencies is determined by the relation 1, the R, T. This perfectly explains why in the case of BS in the form of prisms, you can usually use the standard HOM theory. In the case when A new physical quantity appears in the theory presented, which characterizes BS and its interaction with photons Eq.  is \docud in Eq. . In othe37. Indeed, when using frequency filters, the spectral amplitude (JSA) It should be added that the dependence on the frequencies of reflection and transmission coefficients cannot be represented as a function of the optical spectral filters, which are often used in experiments e.g.from Eq. , the coementclasspt{minima


Ntotal = 70) and apparent dominant inheritance pattern were included in this study. Genotyping was performed in 37 family members, and WES was additionally carried out in 10 of those. Linkage analysis was performed using multi-point analysis in Superlink Online SNP 1.1. From prioritized linkage regions with a LOD score ≥ 2, a total of 24 genes harboring rare variants were selected. Those genes were taken forward and were jointly analyzed in gene-set analyses of exome-chip data using the MAGMA software in an independent sample of patients with persistent ADHD and healthy controls (N = 9365). The gene-set including all 24 genes together, and particularly the gene-set from one of the three families (12 genes), were significantly associated with persistent ADHD in this sample. Among the latter, gene-wide analysis for the AAED1 gene reached significance. A rare variant (rs151326868) within AAED1 segregated with ADHD in one of the families. The analytic strategy followed here is an effective approach for identifying novel ADHD risk genes. Additionally, this study suggests that both rare and more frequent variants in multiple genes act together in contributing to ADHD risk, even in individual multi-case families.Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder with a complex genetic background, hampering identification of underlying genetic risk factors. We hypothesized that combining linkage analysis and whole-exome sequencing (WES) in multi-generation pedigrees with multiple affected individuals can point toward novel ADHD genes. Three families with multiple ADHD-affected members ( CDH13 gene was repeatedly found among the top-findings in GWASs [ADGRL3/LPHN3 gene as an ADHD risk factor [Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial neurodevelopmental disorder, characterized by age-inappropriate inattention, hyperactivity, and increased impulsivity. ADHD is frequent in children, and in up to 60% of the cases impairments persist into adulthood . ADHD prin GWASs . In addik factor , 16. Mork factor –21 and ik factor  and wholk factor , 24. In k factor , 26).N = 9365 [In this study, we explored whether a combination of linkage analysis and WES in large multi-generational pedigrees is a viable approach to gene-finding in ADHD. We narrowed down the search area for rare variants by linkage analysis in three multi-generation pedigrees with multiple ADHD-affected members. Based on the WES applied to subsets of family members, we selected rare variants present in all (suggestive) linkage regions in each family. In line with the polygenic nature of ADHD, in which both common and rare genetic variants are likely to contribute to disease etiology, we subsequently used the extracted gene-sets to analyze the cumulative role of common and rare variants in persistent ADHD in an independent exome-chip data set .Ntotal = 70, NADHD = 41). The structure of the three families  is summarized in Table The study included three multi-generational families with multiple ADHD affected individuals (www.nijmegenbiomedischestudie.nl), a population-based survey conducted by the Departments of Epidemiology & Biostatistics and Clinical Chemistry of the Radboud University Medical Center [The data set, which did not include members of the families above, was genotyped on the Infinium Human CoreExome chip  and comprised 1846 adults with persistent ADHD and 7519 controls recruited from four different countries: Spain (615 cases and 932 controls), Norway (597 cases and 2598 controls), Germany (340 cases and 2 286 controls), and The Netherlands (294 cases and 1703 controls). Part of the Dutch controls were derived from the Nijmegen Biomedical Study . The stP ≤ 10−6). The remaining 665,362 SNPs were pruned to reduce linkage disequilibrium (LD) between markers using PLINK v1.07 software . Microarray quality control parameters and genotype calls were generated with Affymetrix Genotyping Console v4.2.0.26 software . Individuals were excluded if their call rate was below 97%. Genotyping data were filtered by removing SNPs with minor allele frequency (MAF) < 5%, missing genotypes > 5%, Mendelian errors > 10% for variants, or deviations from Hardy–Weinberg equilibrium  with pa33.Multi-point linkage analyses of genome-wide SNP data were performed using Superlink Online SNP 1.1 , which cTM System . High quality reads were mapped to the hg19 reference genome (UCSC genome browser) using the Lifescope 2.1 software (http://www.lifetechnologies.com/lifescope/) with default parameters. In addition, the SOLiD Lifescope Software v2.1 was used to call single-nucleotide variants (SNVs) using the diBayes algorithm. Variant annotation was done at the Department of Human Genetics of the Radboud university medical center using a pipeline developed in-house [http://www.ncbi.nlm.nih.gov/SNP/), and (iii) variants present in all sequenced family members. Functional effects of variants were predicted by three different softwares: SIFT [For each family, two or more affected family members were strategically selected for WES based on meiotic distance and/or position in the pedigree Table . Genomicin-house . Variantes: SIFT , PolyPhees: SIFT , and Mutes: SIFT . Conserves: SIFT  and Granes: SIFT .http://ctglab.nl/software/magma [P < 0.0042).The cumulative effect of common and rare variants in selected genes and gene-sets was tested using the independent, recently published IMpACT exome-chip data set (re/magma ) and there/magma . Data weP-value level < 0.05.To assess whether the 12 prioritized genes from family P2 converge on biological shared functions, we tested for enrichment in Gene Ontology (GO) terms for biological processes using FUMA . OverrepTo validate the presence of selected rare variants in the two sequenced individuals and to allow segregation analysis, all individuals of family P2 were genotyped for chr9:99404124G>C (rs151326868) and chr8:124346225T>C using PCR-based DNA sequencing. The locus of interest was amplified by conventional PCR and sequenced by direct Sanger sequencing (details and primer sequences are available upon request). Data obtained for the two variants were used to analyze the segregation with ADHD diagnosis.The main aim of the linkage analyses was to provide an additional filtering step for the WES data by narrowing down the genomic regions of interest. Linkage analysis was performed for each family individually, but also for all possible combinations of the three families. Informative individuals from each family were enrolled in the linkage study: nine individuals from family P1, 19 individuals from family P2, and 16 individuals from family P3 , two from family P2 (ID21 and ID26), and three from family P3 ) . Another gene in this gene set—ATAD2—yielded suggestive significance after correction for multiple testing  and ‘cell–cell adhesion via plasma membrane adhesion molecules’ (Padjusted = 0.0328) . Four significantly enriched GO-terms were detected, including ‘regulation of vesicle fusion’ (AAED1 and ATAD2) from the gene-based analysis. The variant rs151326868, located in AAED1 (chr9:99404124G>C), was predicted to be deleterious in all pathogenicity tests , was highly conserved . The SNV chr8:124346225T>C in ATAD2 was predicted to be deleterious only by MutationTaster, showed low conservation scores, and had very low MAF in the ExAC browser  carried at least one of the two variants, and 60% of the affected individuals (9/15) carried both variants  segregated with ADHD in family P2.In this study, we aimed to identify novel genetic risk factors for ADHD by combining linkage analyses and WES in multi-generation families. We predicted that through a family-based approach, we would be able to limit genetic heterogeneity, since rare variants with potentially higher penetrance may cause the disorder in familial ADHD cases. Linkage analyses revealed four genomic regions with a LOD score ≥3.3 and 15 additional regions with a LOD score ≥2. Within these regions, we identified 38 rare variants within 25 genes across the three families. All genes together, and particularly the gene-set from family P2, were significantly associated with persistent ADHD in the independent exome-chip sample. Moreover, the Different designs can be used for WES studies aiming at identifying rare variants linked to complex diseases. In schizophrenia  and ASDsAAED1 would remain. Utilizing this independent sample, we showed that (some of the) identified genes may be relevant to ADHD in the population, thereby generalizing the findings from the single family. This approach also enabled us to study the cumulative effect of rare and common genetic variants in the identified candidate genes for association with persistent ADHD, maximizing power to find association by taking into account allelic heterogeneity [We extended the family-based approach by testing the effects of observed genes carrying rare variants in an independent, large sample of exome-chip data. Importantly, most of the selected rare variants in the genes included in the gene-set analysis of family P2 are exonic and non-synonymous variants, so the overall result in the case–control analyses would not be affected by more stringent selection criteria for rare variants that are frequently used in WES studies . Specifically, the significant gene-based association of ogeneity , 22.Importantly, our work supports the notion that—despite the apparent dominant segregation pattern - ADHD is not a monogenic disorder in the pedigrees investigated. Linkage analyses revealed several (suggestive) signals per family, suggesting that several genes/loci may carry risk variants for ADHD in each of those. Based on the linkage analyses, we did not expect a single gene or single locus to be associated with the clinical phenotype nor perfect co-segregation pattern of the rare, non-reference allele with ADHD in subsequent segregation analyses. A main contributing factor to the observed patterns may be assortative mating, which is common in ADHD  (and e.gAAED1 gene (coding for the AhpC/TSA Antioxidant Enzyme Domain Containing 1 protein) was significantly associated with persistent ADHD in the exome-chip sample, and the rare variant in this gene  segregated with ADHD risk in family P2. AAED1 strongly binds and interacts with the Protein Kinase C-Alpha-Binding Protein (PICK1) [3 receptors (D3R) has been reported [Pick1 knockout mice show several behavioral abnormalities, such as hyperactivity and electrophysiological deficits in the prefrontal cortex [AAED1, dopaminergic and glutamatergic signaling, and ADHD risk. Thus, studies of the AAED1 variant’s functional impact in carrier-derived neurons of dopaminergic and glutamatergic specification, which have been differentiated from induced pluripotent stem cells (iPSCs), are currently being conducted .The prioritized genes in the gene-set of family P2 converged on the biological function of vesicle fusion, which adds to the relevance of our findings, since the process of vesicle fusion to plasma  membrane is closely related to the mechanism of neurotransmitter release. The  (PICK1) . PICK1 b (PICK1) . Additioreported . Furtherreported , and a rreported . In addil cortex . With thATAD2 gene, coding for the ATPase family AAA domain-containing protein 2, and gene-based analysis of this gene revealed suggestive association with persistent ADHD. However, a neuronal function of this gene has not been described yet.Our combined approach of linkage and WES also identified a rare genetic variant in the AAED1 as a novel ADHD candidate gene, showing that combining linkage analysis and WES can be an efficient strategy to prioritize ADHD-associated genes/variants. In contrast to previous studies focusing on pre-defined gene-sets [The findings described here need to be interpreted in light of several strengths and limitations. Although we considered only three families, we identified ene-sets , 61, we ene-sets , geneticene-sets , 63, 64,ene-sets . MoreoveIn conclusion, we provide evidence for the role of rare variants in protein-coding genes in the etiology of ADHD. Our data adds to the notion that less frequent variants provide an additional source of relevant genetic risk factors, which received little attention in ADHD genetics so far. Moreover, we show that genes harboring rare genetic variants in individual families are associated with persistent ADHD in an independent sample. Therefore, this study suggests that the combination of linkage analyses and WES provides a practical approach for gene identification in genetically complex neurodevelopmental disorders, such as ADHD.Supplementary MethodsSupplementary Figure 1Supplementary Figure 2Supplementary Figure 5Supplementary Figure 3Supplementary Figure 4Supplementary Table 5Supplementary Table 6


The psychological effects of the COVID-19 government-imposed lockdown have been studied in several populations. These effects however have not been studied in adult populations with attention deficit/hyperactivity disorder (ADHD).We wanted to investigate the psychological effects of the COVID-19 imposed lockdown on an adult population with ADHD.We conducted a cross-sectional survey by administering the Patient Health Questionnaire-9, Generalized Anxiety Disorder Scale-7, Brief Adjustment Scale-6, Perceived Stress Scale, and Multidimensional Scale of Perceived Social Support to a pragmatic sample of adults with ADHD.In total, 24 individuals  were included in this study. The adults with ADHD we surveyed had significant levels of emotional distress during the COVID-19 pandemic period. However, there was no evidence of significant deterioration to the mental health of our sample during the COVID-19 pandemic.When treatment for ADHD is maintained, the effects of the COVID-19 pandemic on the mental health of adults with ADHD are mild. Targeted psychological interventions may be useful in such circumstances. Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neuropsychiatric conditions. The pooled worldwide prevalence of ADHD is estimated to be approximately 5% in school-aged children, and impairing symptoms have persisted in adulthood in up to 65% of cases. The pooled estimated prevalence of ADHD in adults is approximately 2.5% . ADHD isIn December 2019, an outbreak of a novel coronavirus pneumonia occurred in Wuhan , and subsequently attracted worldwide attention . As a reAs the lockdown progressed, concerns were raised about the effect of this lockdown on the mental health of individuals . A generThe mechanism behind the impact of the lockdown can be understood by considering the lockdown as an event that has created stressful life events in a person’s life. Stressful life events are described as discrete, quantifiable circumstances that can have a severe negative impact. A wealth of published evidence has shown that life event stressors are associated with the onset of depressive episodes and that there is a dose-response relationship between these stressors and depressive episodes . StressoStress is generally conceptualized as a negative cognitive-emotional state caused by an individual’s perception of difficulty in adjusting to or managing life events . StudiesBased on this context, we believe that adults with ADHD are disproportionately affected by the lockdown compared to other populations. We therefore administered a survey to a group of adults with ADHD to investigate the psychological effects of the COVID-19 imposed lockdown on this population, understand this population’s needs, and provide appropriate support.We conducted a cross-sectional survey study. The convenience sample was derived from the caseload of the ADHD and Autism Service at South West Yorkshire Partnership NHS Foundation Trust. The ADHD and Autism Service provides input to approximately 1.2 million people in West Yorkshire, England, for people with ADHD and autism. The ADHD and Autism Service can only offer pharmacological interventions to people with ADHD aged >25 years. Therefore, only people aged <25 years were eligible for this study. Our survey was considered a service improvement activity because the results of the survey were to be used to identify people who were suitable for COVID-19–specific psychological intervention.Our cohort consisted of 94 individuals with a preestablished diagnosis of ADHD  who were first contacted on May 18, 2020, for a period of 2 weeks over the telephone. After 3 unsuccessful attempts of making contact with an individual, the person was considered not-responding, and no further attempts were made. All individuals were receiving pharmacological treatment.For the people who did respond to the telephone call, after the purpose of the well-being survey was explained using a predetermined script, the Patient Health Questionnaire-9 (PHQ-9) , GeneralThe PHQ-9 and GAD-7 use a scale of 0  to 3 (nearly every day) to measure the severity of self-reported depression and anxiety, respectively, within the last two weeks. They have 9 and 7 questions, respectively. PHQ-9 scores ranging from 0 to 5 represent mild depression, 6-10 represent moderate depression, 11-15 represent moderately severe depression, and 16-20 represent severe depression. GAD-7 scores of ≤4 predict no anxiety, 5-9 predict mild anxiety, 10-14 predict moderate anxiety, and 15-21 predict severe anxiety. The BASE-6 measures a person’s general psychological adjustment within the last week, with ratings between 1  and 7 (extremely) given for each of the 6 questions.The PSS consists of 10 items designed to assess the degree to which common life situations in the past month are deemed stressful, and responses are made using a 5-point scale . Individual scores on the PSS can range from 0 to 40, with higher scores indicating higher perceived stress. Scores ranging from 0 to 13 indicate low perceived stress, 14-26 indicate moderate perceived stress, and 27-40 indicate high perceived stress.The MSPSS measures the perception of support from the following 3 sources: family, friends, and a significant other. The scale is comprised of 12 items on a 7-point Likert scale, with 4 items for each subscale. Higher scores reflect more perceived social support. Mean scores ranging from 1 to 2.9 indicate low perceived support, 3-5 indicate moderate perceived support, and 5.1-7 indicate high perceived support.The results from these scales, along with demographic information, were recorded using Microsoft Excel. The results were then exported to IBM SPSS statistical software for analysis.Of the 94 individuals eligible for the survey, 75 were male and 19 were female. The mean age of the total sample was 22.05 years (SD 1.837 years). Of these 94 individuals, 70  were excluded from this study, either because they could not be contacted or because they refused to take part in this study. Of these 70, 18  declined to take part in this study and 52  could not be contacted. In total, 24 patients  were included in this study. 73t=0.64; P=.53). There was also no significant difference in age between females who were excluded from this study  and included females .There was no significant difference in age between males who were excluded from this study  and included males . Based on our survey results, the mean PSS score was 21.5 (SD 7), the mean MSPSS score was 5.55 (SD 0.89), the mean GAD-7 score was 4.84 (SD 1.46), the mean PHQ-9 score was 10.88 (SD 6.83), and the mean BASE-6 score was 17.13 (SD 9.56).r=.623; P=.01), PHQ-9 , and BASE-6  scores; GAD-7 scores and PSS , PHQ-9  BASE-6  scores; and PHQ-9 scores and PSS , GAD-7 , BASE-6  scores. All correlations were significant at the .01 level and all tests were 2-tailed. There was no correlation between age or MSPSS scores with any other variables , which was similar to the clinical sample  and college student sample (mean 18.1 SD 6.8) scores reported during the evaluation of the BASE-6 . HoweverOur participants’ mean MSPSS score was 5.55 (SD 0.89), which indicated a high level of support. Previous studies that used this scale for people with ADHD ,26 have In this study, the GAD-7, PHQ-9, PSS, and BASE-6 scores positively correlated with each other, suggesting that in circumstances where the impact of stress is poor, psychological adjustment, mood, and anxiety will deteriorate. Based on this, it might be useful to have an available form of psychological intervention specific to current circumstances to prevent further deterioration.We are aware that this study has several limitations; the sample size was small, the dropout rate was high, and the sample was not representative of all adults due to only including people aged 18-25 years. Despite this, our findings provided a window into how adults with ADHD fared with the social changes caused by a global pandemic that restricted their movement and relationships. In our sample, participants seemed to manage the same as their expected baseline, and this may be somewhat explained by the fact that they were able to continue their medication. Our findings also suggest that it may be useful to have an available form of psychological intervention for increasing resilience in adults with ADHD, in case other life events or a prolonged pandemic cause more severe deterioration to their mental health.We expected that adults with ADHD would find the restrictions imposed by the lockdown particularly difficult to adhere to, and as a result, their mental health would be at risk of deterioration. Our findings suggest that there was evidence of mental ill health, but this was not severe or disproportionate to what was expected for this population. This may have been due to all participants continuing their pharmacological treatment for ADHD. However, due to their reported distress, a preventative targeted psychological intervention may be useful.


This account surveys the current progress on the application of intra- and intermolecular enyne metathesis as main key steps in the synthesis of challenging structural motifs and stereochemistries found in bioactive compounds. Special emphasis is placed on ruthenium catalysts as promoters of enyne metathesis to build the desired 1,3-dienic units. The advantageous association of this approach with name reactions like Grignard, Wittig, Diels–Alder, Suzuki–Miyaura, Heck cross-coupling, etc. is illustrated. Examples unveil the generality of such tandem reactions in providing not only the intricate structures of known, in vivo effective substances but also for designing chemically modified analogs as valid alternatives for further therapeutic agents. Alkene and alkyne metathesis –4, constEnyne metathesis is a fundamental chemical transformation involving an alkene and an alkyne to produce a dienic structure through unsaturated bond reorganization –46. ThisIt should be pointed out that enyne metatheses are atom economical processes driven by the enthalpic stability of the conjugated diene products. Depending on the steric requirements of the transition metal carbene and of the starting enyne, the intramolecular reaction can proceed either via ene–yne or yne–ene pathways to yield the respective dienic compounds  52]..52].exo or endo isomer, in compliance with the required stereochemistry of the final product. For the intermolecular enyne metathesis reaction, the double bond of the alkene is coordinated to the metallacarbene and cleaved . After selecting the optimal tricyclic intermediate, the installation of the bridged peroxide groups in the corresponding artemisinin analog was eventually achieved by applying further oxidation.Due to its biological relevance, artemisinin, a tricyclic compound bearing a peroxide bridge, has been subject of extensive scientific investigations during the last decade –63. In t, I–VIII , as suit2), a potent neuroprotective agent, by successfully applying a tandem ring-closing metathesis of dienynes and subsequent Eu(fod)3-catalyzed intermolecular Diels–Alder cycloaddition and epoxidation reactions , a3) (3).Amphidinolides constitute a broad family of natural macrolides that act as powerful cytotoxic agents against various cancer cell lines. Due to the stereochemical intricacy and high cytotoxicity, these compounds have attracted a great deal of attention from synthetic chemists. The application of an intermolecular enyne metathesis in tandem with a diene cross-metathesis as the crucial steps were reported by Lee in the total synthesis of (−)-amphidinolide E (3)  70]. It. It3) (7E-isomer (E/Z = 7.5:1). The functionalization of the dienic compound through a Suzuki–Miyaura coupling and Julia–Kocienski olefination, followed by a Yamaguchi lactonization, and an asymmetric epoxidation in the presence of (+)-diethyl tartrate, conveniently produced (−)-amphidinolide K  in 33 total steps (22 longest linear). To this end, after three generations of synthetic attempts, they succeeded joining the northern and southern fragments of des-epoxy-amphidinolide N, both endowed with a considerable level of structural complexity, by essentially using a Ru-catalyzed alkene–alkyne (Ru-AA) coupling reaction and a macrolactonization step  the intermediate diene fragment .des-epoxy-amphidinolide N, including a palladium asymmetric allylic alkylation (Pd-AAA), a Mukaiyama aldol reaction (with Sn), and a Krische allylation (with Ir) diazocin-6-one) (21), two important pharmacologically active compounds containing dipiperidine and piperidino-quinolizidine units in their structure. Starting from the monoacetate of cyclopentene-1,4-diol that was obtained by the enzymatic desymmetrization of the corresponding diacetate, an enyne metathesis precursor was accessed by a Mitsunobu-type coupling reaction with propargylic amide. The ring-rearrangement metathesis (RRM) of this enyne precursor was carried out using the second-generation Hoveyda–Grubbs catalyst , under an ethylene atmosphere. The subsequent regioselective NaIO4-mediated oxidative cleavage of the pendant double bond, followed by the installation of the unsaturated N-butenyl group, oxidation, and deprotection provided the final products 20 and 21 , a potent bioactive compound, by ring-closing enyne metathesis in the presence of the Grubbs first-generation Ru catalyst. According to this method, an enyne precursor was first converted into an exocyclic 1,3-diene in 92% yield. A Diels–Alder reaction with naphthoquinone and a deprotection step then led to the final compound (−)-zenkequinone B in a stereoselective manner  in high yields  was reported by Roulland et al. [The first stereoselective synthesis of the (−)-exiguolide enantiomer (d et al. . The metThis review highlighted the most recent efforts regarding the development of enyne metathesis-based syntheses of complex bioactive, natural and nonnatural organic molecules. Both, intra- and intermolecular enyne metatheses have been valorized to efficiently produce key 1,3-dienic frameworks, further subjected to sequential functionalization. The main focus was placed on strategies combining enyne metathesis with traditional chemical transformations such as Diels–Alder cycloaddition, Suzuki–Miyaura or Heck cross-couplings, aromatization, epoxidation, hydroxylation, etc. This point of view has allowed to master a concise access to the target products which require exceptional chemical and stereochemical complexity. The excellence of the Grubbs- and Schrock-type metathesis catalysts as selective and proficient promoters of enyne metathesis was emphasized. The review also shed light on the continuous improvement of protocols relying on this reaction, potentially leading to tailorable properties of earmarked therapeutic agents.