To explore the specific alterations of white matter microstructure in children with attention-deficit/hyperactivity disorder (ADHD) by automated fiber quantification (AFQ) and tract-based spatial statistics (TBSS), and to analyze the correlation between white matter abnormality and impairment of executive function.DKI), axial diffusivity (ADDKI), radial diffusivity (RDDKI) and fractional anisotropy (FADKI) of DKI and AD, RD, MD, and FA of diffusion tensor imaging (DTI) assessed the integrity of the white matter based on TBSS. Partial correlation analyses were conducted to evaluate the correlation between white matter abnormalities and clinical test scores in ADHD while taking age, gender, and education years into account. The analyses were all family-wise error rate (FWE) corrected.In this prospective study, a total of twenty-seven patients diagnosed with ADHD  and twenty-two healthy control (HC) individuals  were included. All participants were scanned with diffusion kurtosis imaging (DKI) and assessed for executive functions. AFQ and TBSS analysis methods were used to investigate the white matter fiber impairment of ADHD patients, respectively. Axial diffusivity (AD), radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA) of 17 fiber properties were calculated using the AFQ. The mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MDp < 0.05). Minor variances existed in gender and age between ADHD and HC, but these variances did not yield statistically significant distinctions. There were no significant differences in TBSS for DKI and DTI parameters . Compared to HC volunteers, the mean AD value of right cingulum bundle (CB_R) fiber tract showed a significantly higher level in ADHD patients following the correction of FWE. As a result of the point-wise comparison between groups, significant alterations  were mainly located in AD  and MD (nodes 92–95) of CB_R. There was no significant correlation between white matter diffusion parameters and clinical test scores in ADHD while taking age, gender, and education years into account.ADHD patients performed worse on the Behavior Rating Inventory of Executive Function (BRIEF) test (The AFQ method can detect ADHD white matter abnormalities in a specific location with greater sensitivity, and the CB_R played a critical role. Our findings may be helpful in further studying the relationship between focal white matter abnormalities and ADHD. ADHD isThere is growing evidence that ADHD is associated with abnormal white matter microstructure . FollowiAt present, studies on white matter changes in ADHD are mostly based on diffusion tensor imaging (DTI) . SeveralIt is possible that tissue diffusion characteristics vary along each node of the fiber tract, as diseases injury may occur in some local positions of the bundle. Despite the fact that the majority of studies have found that there are white matter injuries in ADHD, it remains unclear whether the specific properties of white matter abnormalities are different along each fiber tract. Thus, the application of a new automated fiber quantification (AFQ) analysis method is particularly important. Using deterministic tractography, AFQ recreates white matter tracts throughout the brain, so more node-detailed information about white matter changes along each fiber tract could be assessed at an individual level . ResearcFurthermore, crossing fibers can be detected much more accurately with diffusion kurtosis imaging (DKI) than with DTI . A compa2.2.1.The local ethics committee of Taihe Hospital in Shiyan City approved this prospective study. Informed consent forms were signed by all parents of participating children before the study.Between August 2022 and February 2023, an MRI screening was conducted on a cohort comprising forty-one ADHD patients and thirty-three healthy controls (HC). The healthy controls were recruited through advertising, while the patients with confirmed ADHD were sourced from our outpatient ADHD clinic. A total of fourteen individuals diagnosed with ADHD and eight healthy control volunteers were excluded from the study due to inadequate image quality or noncompliance with the inspection procedures. Three additional volunteers diagnosed with arachnoid cysts were excluded from the HC group. This study finally included twenty-seven patients with ADHD  and twenty-two healthy volunteers . The clinical diagnostic criteria of ADHD were fulfilled according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and confirmed either by clinical assessment, both the ADHD indices of parent and teacher were ≥ 75th percentile, which was deemed to be positive for ADHD.All participants were all 6–13 years of age, right-handed, and did not have any contraindications for MRI scanning. Patient exclusion criteria included: (a) psychiatric diseases other than ADHD, such as depression, anxiety, tic disorder, schizophrenia, etc. (b) medical conditions that may affect brain structure or function, such as craniocerebral trauma, intracranial space-occupying lesions, metabolic disease, hereditary diseases, or other disorders of the central nervous system. (c) MRI contraindications. (d) history of regularly consuming drugs. A healthy control group was recruited with similar age, gender, and education level to the ADHD group and excluded the diagnosis of ADHD. Exclusion criteria for HC: (a) psychiatric diseases, such as ADHD, depression, anxiety, tic disorder, schizophrenia, etc. (b) other exclusion criteria were the same as those for ADHD group.2.2.Clinical data including age, gender, and education years were collected from all subjects. The clinical assessments were completed by an associate chief pediatrician who possesses 12 years of professional experience, including Swanson Nolan and pelham-IV rating scale (SNAP-IV) and the Behavior Rating Inventory of Executive Function (BRIEF).The SNAP-IV evaluation includes an attention defect score and a hyperactivity score. BRIEF containing 86 items was used for children aged 6 and older to determine executive function abilities. There are two components to the questionnaire: a Behavioral Regulation Index (BRI) and a Metacognition Index (MCI). As part of the BRI, the following three clinical scales are described: inhibit, shift, and emotional control. MCI is composed of the initiate, working memory, plan, organization of materials, and monitor. The original scores of each factor were calculated as T scores after age and gender correction.2.3.MRI examinations of all participants were performed on a 3.0-Tesla MRI scanner  equipped with a 48-channel phased-array head coil. In order to reduce noise and minimize head movement, earplugs were used, as well as tight foam padding.2) and one non-diffusion weighted image (b = 0 s/mm2), flip angle (FA) = 90o, repetition time (TR) = 8,819 ms, echo time (TE) = 90.4 ms, field of view (FOV) = 240 mm × 240 mm, matrix = 120 × 120, NEX = 1, voxel size = 2 mm × 2 mm × 2 mm, slice gap = 0 mm, 75 axial slices, the total acquisition time was 9 min 7 s. Anatomical 3D gradient-echo T1-weighted images were obtained using a 3D gradient-echo sequence to obtain a high-resolution volume image .DKI data were obtained using a single-shot spin echo planar imaging (EPI) sequence with the following parameters: diffusion encoding was applied in 60 directions with two b values , axial diffusivity (ADDKI), radial diffusivity (RDDKI), and fractional anisotropy (FADKI) were calculated using the diffusional kurtosis estimator (DKE). Furthermore, images with b = 0 and 1,000 s/mm2 were extracted to calculate parameters  of the DTI model by using FSL software. The dcm2nii tool in MRIcron was also used to convert 3D T1WI DICOM images into NIfTI format, then the script mrAnatAverageAcpcNifti and dtiMakeDt6FromFsl were used to align AC (anterior commissure) -PC (posterior commissure) and obtain a dt6 MATLAB format file.A visual inspection of all images was conducted to ensure that only images without visible artifacts were included in the analysis. DKI digital imaging and communications in medicine (DICOM) images were converted into NIfTI (.nii) format and automatically generated b-vectors and b-values using the dcm2nii tool in MRIcron.2.5.DKI, ADDKI, RDDKI, FADKI, MD, AD, and RD images for statistical analysis. To assess the differences in voxel-wise FA, MK, AK, RK, MDDKI, ADDKI, RDDKI, FADKI, MD, AD, and RD between the two groups, the individual skeleton images were subjected to a general linear model (GLM) analysis. Age, sex, and years of education were included as covariates in the analysis. Nonparametric permutation-based testing was conducted using the randomize function in FSL.p < 0.05 level after 5,000 permutations, employing permutation-based non-parametric inference. Threshold-free cluster enhancement (TFCE) and family-wise error (FWE) rate correction were applied to account for multiple comparisons.The diffusion tensor imaging data underwent processing with the Functional MRI of the Brain (FMRIB) Software Library (FSL) version 5.0.9.2.6.In this study, we identified twenty major fiber tracts of the whole brain and applied AFQ software2.7.The statistical package for social science (SPSS) version 25.0 was used to analyze the clinical data and the mean values of DTI parameters (AFQ) for each fiber tract between ADHD and HC group. Comparing normally and non-normally distributed variables was carried out using independent samples t-tests or Mann–Whitney U-tests. Statistical tests were conducted on enumeration data using Chi-squared or Fisher’s exact tests.p < 0.05/68). A point-wise analysis was performed using the “Randomize” command in FSL, as covariates in the GLM model, gender, age, and education years were controlled. Based on 5,000 permutations, a non-parametric permutation-based statistical analysis with FWE (p < 0.05) was performed on 1,700 points. As a result, we only reported the results of ≥3 adjacent nodes among those with significant differences. Partial correlation analyses were conducted to determine if the microstructural integrity of white matter correlated with clinical test scores while taking age, gender, and education years into account.In the statistical analysis conducted using the AFQ method, the average values of DTI parameters  of each fiber tract in the two groups were compared, and multiple comparisons were corrected by FWE correction (3.3.1.p > 0.05). Compared with HC volunteers, ADHD patients performed worse on concentration tests and the BRIEF test and showed significant impairments in inhibit, shift, emotional control, initiate, working memory, plan, organization of materials, and monitor (p < 0.05).Statistical results for demographic and clinical characteristics can be found in 3.2.DKI, ADDKI, RDDKI, FADKI, FA, MD, AD, and RD .There were no significant differences in tract-based spatial statistics for MK, AK, RK, MD3.3.3.3.1.The mean value of each fiber tracts for FA, MD, AD, and RD were presented in The mean AD values for the 16 remaining fiber tracts, as well as the mean FA, MD, and RD values for the 17 fiber tracts, all showed no significant differences after FWE correction –5.3.3.2.p < 0.05) were mainly located in AD  and MD (nodes 92–95) of CB_R, details about the significant differences are shown in In order to show detailed diffusion properties of tracts, pointwise comparisons between ADHD patients and HC volunteers were quantified based on AFQ software, white matter disruption is found in specific parts along the white matter tract in ADHD patients. As a result of the point-wise comparison between groups, significant alterations  and MD (nodes 92–95) of CB_R, there was no significant correlation between white matter diffusion parameters and clinical test scores in ADHD while taking age, gender, and education years into account.4.ADHD patients exhibit specific subcortical dysfunction, with prevailing belief that subcortical abnormalities play a role in the onset of ADHD, while cortical plasticity influences the diverse clinical trajectory of the disorder . The thaThis study examines the precise modifications in white matter microstructure in children with ADHD through the utilization of AFQ and TBSS. While previous neuroimaging investigations of ADHD have evaluated the integrity of the white matter, the TBSS study outcomes based on voxels did not survive following multiple comparison corrections in this particular study of children. One plausible explanation is that TBSS may be better suited for detecting significant white matter abnormalities . For insThe cingulum bundle is a white matter pathway that extends longitudinally from the anterior cingulate cortex (ACC) to the posterior cingulate cortex (PCC), linking the components of the default mode network (DMN) and providing important limbic connections, including those to supplementary motor and primary motor regions . This laThere exists a substantial body of evidence indicating that ADHD is linked to deficiencies in various neurocognitive domains. Neuropsychological theories posit that ADHD is chiefly marked by executive dysfunction  and anomAt a point-wise level, the AFQ technique enables the measurement of diffusion at 100 equidistant nodes along the fiber tract. In contrast to prior methodologies, this approach affords a more precise analysis of tracts, yielding more accurate identification of damage segments and greater sensitivity to abnormalities in other indicators. The present investigation revealed significant alterations primarily in the AD  and MD (nodes 92–95) of CB_R. The findings of our study suggest that ADHD patients exhibit injury predominantly in the anterior and posterior regions of the CB_R fiber tract, which is manifested by elevated AD and MD values. Prior research has demonstrated that changes in AD and MD may be indicative of axonal damage  and myelFurthermore, our study revealed no statistically significant alterations in FA along fiber tracts. Our findings are consistent with previous research, which has demonstrated that there are no significant differences in FA within the white matter structure of the cingulum tract between individuals with ADHD and healthy controls . HoweverThe results of our study indicate that the altered white matter parameters observed in individuals with ADHD were not found to be significantly correlated with clinical test scores. However, the ADHD group exhibited significantly higher scores in attention deficit and hyperactivity, as well as in the areas of inhibition, shifting, emotional control, initiation, working memory, planning, organization of materials, and monitoring, thereby confirming the presence of executive function deficits in this population.An AFQ analysis of adults with ADHD found that there were no differences between ADHD and HC, and the ADHD group showed no significant association , this co4.1.To the best of our knowledge, this investigation represents a pioneering effort in scrutinizing the precise locations of individual fiber tracts in children with ADHD utilizing the AFQ. Nonetheless, it is imperative to acknowledge certain constraints of this study despite its merits. Firstly, our prospective inquiry was executed on a modest sample size, and additional research is necessary on a more comprehensive sample. Secondly, there was no categorization for ADHD, and future investigations will necessitate a thorough analysis of diverse subtypes of data. Thirdly, the present study was limited by the absence of longitudinal research as all patients were diagnosed during their initial visit. Future studies should investigate the impact of disease progression on white matter microstructure. Fourth, certain fibers, including CH_L, CH_R, and AF_R, were not trackable due to threshold settings in fiber tracking. Fifth, the correlation analyses indicated that the altered white matter parameters did not exhibit a significant correlation with clinical test scores in ADHD, possibly due to the small sample size and the effect of mixing multiple subtypes.5.According to the AFQ method, capable of detecting mild changes in white matter, we identified white matter abnormalities in fiber tracts with a greater degree of spatial precision. As a surveillance tool for ADHD, the AFQ method can detect ADHD-related white matter abnormalities with greater sensitivity, and the CB_R played a critical role in furthering our understanding of ADHD-related white matter abnormalities. Our findings may be helpful in further studying the relationship between focal white matter abnormalities and ADHD.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving humans were approved by Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.RH and FT: study design, data collection and curation, image scanning and post-processing, formal analysis, visualization, and writing-original draft. WC, YW, YJ, WD, YZ, and BG: case collection, investigation, data curation, image post-processing, software application, formal analysis. QS: scanning specification, technical guidance, supervision. YM: conceptualization, study design, funding acquisition, supervision, and writing – review and editing. All authors contributed to the article 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


E. Medea  for ADHD pharmacotherapy initiation and monitoring overtime. The main aim of the study was to examine differences in pharmacological treatment status  between patients.The present study analysed data on children and adolescents with a diagnosis of attention-deficit/hyperactivity disorder (ADHD) who were referred to the ADHD reference centre of Scientific Institute IRCCS Seventy-seven children and adolescents  with ADHD received drugs treatment for ADHD at the reference center between January, 2013 and May, 2022. Demographic and clinical data were obtained from the Italian Registry for ADHD and medical records. Child Behavior Checklist (CBCL) available data were used.n = 63) with at least 12 months of follow-up after the first pharmacological treatment for ADHD. After starting pharmacotherapy treatment, 77.8% (n = 49) patients were still on treatment whereas 22.2% (n = 14) discontinued it. No between group difference were observed in demographic and clinical data except for the intelligence quotient/intellectual disability and rule-breaking behavior (n = 40).Pharmacological treatment status was examined for patients (This study stressed the need of periodical assessments, monitoring difficulties with treatment and/or reasons for poor treatment compliance to provide individualized care. Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by age-inappropriate levels of attention and/or impulsivity lasting for at least 6 months . In ordeADHD in the Italian young population shows a prevalence of 2.9% (range: 1.1–16.7%). Prevalence of clinically confirmed ADHD diagnoses drops to to 1.4% (range: 1.1–3.1%) .SINPIA   GuidelinThe Italian National Registry for ADHD was set up in 2007 to monitor ADHD drugs use in childhood and adolescence and assess safety, benefits and compliance –19. ChanPatients on drugs more commonly presented symptoms of clinical severity , combined type of ADHD, clinical dis-attention and hyperactivity (as reported by parents) compared to subjects receiving psychological interventions only . In a reIdentifying factors associated with treatment (dis-)continuation may have important clinical implications for individually tailored interventions .Adherence to, and persistence of, ADHD pharmacological treatment are generally low among young people with ADHD and vary between 40 and 70% and 30–50%, respectively –29. Low Few studies examined the relationship between psychopathological symptoms and (dis-)continuation of drug treatment for ADHD reporting mixed findings. Atzori and colleagues  retrospeOther studies which did not differentiate between discontinuation reasons  showed no association between therapy continuation and psychopathology. For example, Palli et al.  did not E. Medea”  between January, 2013 and May, 2022.The first aim of this study was purely descriptive, namely reporting on demographic and clinical characteristics of children and adolescents aged 5 to 17 years who received drug treatment for ADHD at the reference center Scientific Institute IRCCS “The second aim of this study was to contribute to scientific knowledge on the association between (dis-)continuation of ADHD pharmacotherapy, demographic and clinical characteristics, in particular symptoms of psychopathology when initiating ADHD pharmacotherapy. Considering previous mixed findings on the relationship between treatment (dis-)continuation and psychopathology, the study was exploratory in nature and we expected either a higher incidence of psychopathology in patients who continued pharmacotherapy compared to those who did not it , 39 or nE. Medea” in Brindisi  – one of the Apulia reference prescription centres for ADHD pharmacological treatment – between January 2013 and May 2022. Prescription centres are responsible for confirming ADHD diagnosis and monitoring the pharmacological therapy over time. In this Italian region, eight reference prescription centres were accredited as specialist centres for diagnosis and treatment of ADHD [E. Medea” in Brindisi . No other inclusion/exclusion criteria were used.This retrospective study included children and adolescents aged 6–17 who were referred to Scientific Institute IRCCS “ of ADHD . PatientWritten informed consent for drug administration and analysis of clinical data for scientific research was obtained from both parents and patients. Patients are hospitalized to receive their first drug administration, the so-called “testing dose” (5 mg of immediate-release methylphenidate) to monitor for potential side effects and vital signs . If there are no relevant side effects, patients start long-term treatment with modified-release methylphenidate, and a first follow-up takes place after a month. Modified-release methylphenidate is generally administered at a dose ranging from 0.3 to 0.5 mg/kg until a maximum of a single dose of 60 mg/die is reached. In some cases, 5 mg of immediate-release methylphenidate is also administered in the afternoon to help patients do their homework. The drug dose is determined based on the improvement seen in child behaviour and psychosocial functioning. Most patient have an annual “drug holiday” (of approximately two/three months) during summer according to their symptomatology, in order to decrease the effects of medication on height and weight and assess the need for continuing medication during the early month(s) of the new school year. The research was approved by the local Ethics Committee, “Research Ethics Committee – IRCCS Istituto Tumori Giovanni Paolo II - Bari .”The following demographic and clinical data was obtained from the Registry for ADHD and medical records: age at treatment initiation, sex, hometown, months between diagnosis and pharmacotherapy, months of pharmacotherapy, intelligence quotient (IQ), subtype of ADHD diagnosis, comorbidity and pharmacological treatment status. IQ was measured using the Wechsler Intelligence Scale for Children (WISC-III and -IV), the Leiter International Performance Scale – Revised (Leiter-R), and the Wechsler Preschool and Primay Scale of Intelligence (WPPSI-III). ADHD diagnosis subtype and comorbidities were diagnosed according to the DSM-IV-TR and DSM-5.Pharmacological treatment status was defined as “on-treatment” and “treatment discontinuation” as of May 2022, and follow-up data of at least 12 months after the first administration of ADHD drug therapy had to be available.The Child Behavior Checklist (CBCL/6–18) , 46 was n = 63) with at least 12 months of follow-up data after the first administration of ADHD drug therapy as of May 2022.Descriptive statistics  were computed to explore the characteristics of the sample and subgroups according to pharmacological treatment status. Subgroup analysis based on pharmacological treatment status included participants (p < 0.05 or approaching significance at p < 0.10) Welch homogeneity correction was applied. Effect size for Cramer’s V was interpreted as moderate if between .2 and .6, and strong if higher than 0.6. For Cohen’s d, it was interpreted as moderate if between .5 and .8, and strong if higher than .8.Between-group differences according to pharmacological treatment status were analysed using the Chi-square test and Student’s t-statistics for group comparison on categorical and continuous variables, using Cramer’s V and Cohen’s d as estimate of effect size, respectively. When the assumption on equality of variance (tested using Levene’s test) was violated (model 1) and psychopathology as measured by the CBCL subscales (model 2), including variables whose bivariate associations were significant (p < 0.05) or approaching significance (p < 0.10) based on subgroup analysis. Model 2 included only participants (n = 40) for whom CBCL data were available. For some children and adolescents, CBCL data were missing as they had been evaluated for ADHD diagnosis by child and adolescent neuropsychiatrists and were later referred to Scientific Institute IRCCS “E. Medea” for their first prescription of ADHD pharmacological therapy and monitoring over time. In this cases, no new (complete) diagnostic assessment is carried out. During a preliminary analysis, differences between participants, whose data was considered for subgroup comparisons  were explored, and no differences in demographic and clinical characteristics were found.Subsequently, two multivariate logistic regression models were used to test associations between pharmacological treatment status and variables of interest  of patients were diagnosed with combined type of ADHD, 6.5% with the inattentive type and only one (1.3%) with the hyperactive one.77% of patients showed one or more comorbid disorder as follows: 54.6% one, 19.5% two, 1.3% three and 1.3% four disorders. The most frequent comorbid conditions were disruption and impulse control disorders, intellectual and learning disability.Nearly all patients (97.4%) received at least one intervention other than pharmacotherapy: 52% of patients received one other intervention, 44.2% two and 1.3% three other interventions. The most frequent interventions were cognitive-behavioral therapy and parent training.p value of 0.091).63 out of 77 patients had at least 12 months of follow-up after their first pharmacological administration for ADHD as of May 2022. Of these, 14 (22.2%) patients discontinued ADHD pharmacotherapy. As expected these two groups differed in the total months of ADHD pharmacotherapy  with higher symptoms in patients who discontinued vs patients who continued ADHD pharmacotherapy (Table p = 0.047) higher mean T total score compared to patients who continued treatment.Considering between-groups comparisons on the CBCL, differences in externalizing and rule-breaking behaviour were borderline significant . Patients on treatment were significantly (χ2 (1) = 3.971, p = 0.046, Cramer’s V = .32) less likely to show intellectual disability  compared to those who discontinued treatment  whereas no other difference was shown for demographic and clinical data. Thus, model 2 included intellectual disability and the CBCL rule-breaking behavior subscale. Results are shown in Table p = 0.032), and intellectual disability (p = 0.028).To test model 2, bivariate associations were computed considering only participants with CBCL data  young patients discontinued ADHD pharmacotherapy after a mean of 12 (SD = 14.2), whereas the rest  remained on treatment for a mean period of 51 months (SD = 25.3). This is consistent with the scientific literature on the topic [Our findings demonstrated that one in five  for whom CBCL data were avaible, intellectual disability and rule-breaking behavior were associated with pharmacological treatment status. Patients with high rule-breaking behaviour and intellectual disability were more likely to discontinue ADHD treatment. These findings were unexpected since previous studies mainly showed no differences between groups [Considering group differences according to pharmacological treatment status, a trend for group difference for IQ emerged. Patients on treatment showed a higher mean IQ score than patients who discontinued treatment. On the other hand, no significant differences were observed for age at diagnosis, age at first intake of pharmacotherapy and other demographic characteristics, diagnosis, comorbidity and other interventions. Further, considering the subsample  of pharmacological and non-pharmacological treatment of ADHD – including 190 randomised trials that enrolled 26,114 young participants with ADHD – seems to support the superiority of behavioural therapy in combination with stimulants compared to other treatments for ADHD, both in terms of efficacy and acceptability. Our findings stress the importance of paying special attention to patients’ intelligence quotient /intellectual disability and rule-breaking behaviour to improve treatment continuation. Methodological issues, such as short follow-up, risk of bias, industry sponsorship should be carefully considered by future research (53). In point of fact, in a meta-analysis of 63 studies enrolling 11,788 young patients Riera et al. (54) found that efficacy was smaller for treatment studies in which a psychiatric comorbid disorder was an inclusion criterion, while it was larger in studies with a commercial sponsorship and showed a negative association with treatment length.n = 58 (75.3% of the sample) and was measured using the WISC , the Leiter-R  and the WPPSI-III . The IQ was not available for two young patients as they had been diagnosed by external neuropsychiatrists and a complete diagnostic assessment was not repeated at Scientific Institute IRCCS “E. Medea” . Use of distinct IQ scales was not associated with treatment status nor with IQ score . Finally, the lack of pathients’s self-reported data on reasons for discontinuation, parental/family and social characteristics may limit the interpretability of our findings since adherence in young people could be determined or at least influenced by these factors [The study was conducted with a population of participants from a geographic and cultural area, namely an ADHD reference centre located in a Southern Italian region. Thus, its results may not be generalized to other different populations or settings. The retrospective design of the study and the small sample size may also limit generalizability of results. Further, data were collected in an ADHD clinical routine management context rather than for specific research purposes. IQ was available for  factors , 41, 43.Despite these limitations, the present study included data on patients in a clinical setting incorporating real-life variability in psychopathological symptoms at presentation (no exclusion criteria applied) supporting its ecological validity.Our findings showed that a higher frequency of intellectual disability and higher rule-breaking behaviour pre-medication in patients who eventually discontinued therapy, compared to patients who continued treatment. This highlights the need for periodical assessments monitoring difficulties with and/or reasons for poor treatment compliance as well as side effects to provide individualized care.


There was no previous meta-analysis investigating the efficacy/tolerability of psychostimulants for symptoms of attention-deficit hyperactivity disorder (ADHD) in preschool children.Databases including PubMed, the Cochrane Library, EMBASE, ScienceDirect, and ClinicalTrials.gov were searched from inception to March 2022 for randomized controlled trials (RCTs) on therapeutic efficacy of psychostimulants against ADHD symptoms in preschool children (age ≤6 years) compared with placebos. Primary outcomes were (a) changes in ADHD symptoms evaluated by validated rating scales from parents’/teacher’s observation, or (b) post-intervention improvements in neuropsychological performance. Secondary outcomes were risks of adverse events.Meta-analysis of nine eligible trials including 544 preschool children  supported the efficacy of psychostimulants against global symptoms from observations of parents  and teachers . Efficacy of psychostimulants was also noted against symptoms of inattention and hyperactivity/impulsivity, especially the latter . Moreover, male gender, older age, and longer treatment duration were associated with better efficacy. Regarding adverse events, only the risk of poor appetite was higher in the psychostimulant group (odds ratio [OR]=2.39). However, the qualities of evidence were low to very low, indicating potential discrepancy between the true and estimated effect.Our results showed that psychostimulants might be beneficial for preschool children with ADHD, especially hyperactivity/impulsivity from teachers’ observation, with tolerable side effects. Nevertheless, the true magnitude of the effect needs to be confirmed with more research due to low to very low certainty of the evidence. Attention-deficit hyperactivity disorder (ADHD), which is a neurodevelopmental anomaly with an onset in early childhood, affects approximately 5% of school-age children  as well Both pharmacological  and non-pharmacological treatments  against the symptoms of ADHD are commonly recommended clinical strategies for those diagnosed with ADHD , 7. FocuNevertheless, not only are preschool children with symptoms of ADHD equally susceptible to psychosocial impairments and developmental problems compared to school-aged children  but theyTherefore, the aims of this study were to investigate the efficacy of psychostimulants against the core and global symptoms of ADHD, the associated adverse events, and the factors affecting their effectiveness among preschool children.This systematic review and meta-analysis was conducted according to the PRISMA statement guidelines . We searSupplementary Table S1. All articles with titles meeting the inclusion criteria were retrieved and reviewed in full text. All original studies investigating the effects of psychostimulants were eligible for review. Additional eligible studies were identified by examining the reference lists of the primary articles and relevant reviews.The literature search was conducted by three independent researchers  by using mainly the following two sets of key terms: (preschool) AND (“psychostimulants” or “methylphenidate” or “amphetamine”). The keywords and limitations used for different databases are provided in We aimed at determining the therapeutic efficacy of psychostimulants against the symptoms of attention and hyperactivity/impulsivity as well as global symptoms in preschool children with attentional problems. Eligible studies were as follows: (1) RCTs in human, (2) those recruiting preschool children (defined as those ≤6 years of age) who suffered from any attentional or developmental problems, and (3) clinical trials that compared the therapeutic effectiveness against the symptoms of ADHD including inattention, hyperactivity/impulsive and global symptoms between the psychostimulant and control groups. Studies that enrolled children aged equal to or older than 7 years of age, those that were not RCTs, and those that were not in clinical trials were excluded.Three investigators  independently extracted relevant information from included studies and evaluated the methodological quality of eligible trials using the Cochrane Collaboration risk of bias tools. Data acquired from the studies included the last name of the first author, year of publication, total number of study participants, type of study, sample size of participant in intervention and control groups, gender, intelligence quotient (IQ), and age as well as psychostimulant dosage and duration. The Cochrane Collaboration’s tool was used to evaluate seven domains of risk: selection bias , performance bias (blinding of participants and assessors), detection bias (blinding of outcome assessment), attrition bias (incomplete outcome data), selective outcome reporting, and other bias. The risk of bias of each item was rated as low, high, or unclear (if there was insufficient information). Disagreements among the three investigators were resolved through discussion. The overall qualities of evidence for different outcomes were rated according to the Grading of Recommendations Assessment, Development, and Evaluations (GRADE) scoring system .The primary outcomes were changes in symptoms of ADHD  evaluated by using any clinically validated rating scale from parents’ and teacher’s observation or post-intervention improvements in neuropsychological performance, which were measured by standardized assessment tools such as continuous performance test (CPT). Secondary outcomes were risks of occurrence of adverse events in the psychostimulant group compared with those in the placebo group.For studies in which relevant data were missing, their authors were contacted by email in an attempt to obtain the necessary information. All potentially relevant manuscripts were independently reviewed by two investigators (YC Cheng and YS Cheng). Areas of disagreement or uncertainty were adjudicated by a third investigator (CK Sun).g with 95% confidence intervals for continuous outcomes. For dichotomous outcomes, we calculated the odds ratio (OR). Hedges’ g is related to Cohen’s d and can be interpreted using the same conventions: small (0.2), medium (0.5), and large (0.8) [2 + (SD post-treatment) 2 − (2R × SD pretreatment × SD post-treatment)], assuming a correlation coefficient (R) = 0.5, when the studies did not report them. When only the standard error of the mean (SEM) was reported, SD was calculated by multiplying the SEM by the square root of the sample size. For studies using median and range, mean and SD were estimated using the formula according to the Cochrane guidelines , p < 0.0001, 2I = 57.1%)  .The results of meta-analysis of six trials involving are summarized in = 57.1%) . With re= 78.2%) . Visual n = 3, Hedges’ g = 0.3268, 95% CI , p = 0.0004, I2 = 27.8%)  .Analysis of inattentive symptoms showed a significantly better treatment effect of psychostimulants compared with that of placebo from both parents’ (= 27.8%)  and teac = 0.0%) . Visual g = 0.4510, 95% CI , p < 0.0001, 2I = 27.5%)  .Analysis of four studies focusing on the effect of psychostimulants against the symptoms of hyperactivity/impulsivity revealed a significantly better therapeutic effect of psychostimulants than that of placebo from parents’ observation (Hedges’ = 27.5%) . In addi= 63.4%) . Visual g = 0.2518, 95% CI , p = 0.1762, I2 = 0.0%)  .Only two out of the nine included studies investigated the effect of psychostimulants on attentional performance including omission and commission by using standardized computerized tests , 37. Whi = 0.0%)  and comm = 0.0%) .Visual in = 6, OR = 2.3899 , p = 0.0314). Although the risks of irritability, sleep disturbance, prone to cry, and anxiety were slightly higher in preschool children receiving psychostimulant treatment than those treated with placebos , none of these elevated risks reached statistical significance (Supplementary Table S3a). Analysis of the three studies with available information about blood pressure and heart rate showed no significant difference in these parameters between the psychostimulant and placebo groups (Supplementary Table S3b). The common side effects described in the included studies are summarized in Supplementary Table S4.A comparison of the occurrence of adverse events between the psychostimulant and placebo groups demonstrated that only the risk of decreased appetite was significantly higher in the psychostimulant group than that in the placebo group (Supplementary Table S5). GRADE assessment revealed that the qualities of evidence regarding the study outcomes ranged from low to very low, mainly due to problems of inconsistency and imprecision of study results (Supplementary Table S6).An examination of the robustness of the outcomes from the current meta-analyses with a leave-one-out sensitivity analysis revealed inconsistencies in results regarding the symptoms of inattention from parents’ observation, the symptoms of inattention from teachers’ observation, and the symptoms of hyperactivity/Impulsivity from teachers’ observation, suggesting a tentative nature of these findings , the effect sizes of the previous network meta-analysis were derived from large populations of adults  and children/adolescents . Moreover, the qualities of current evidence supporting the use of psychostimulants in this population ranged from low to very low, mainly due to inconsistency and imprecision of study outcomes, as well as limited sample sizes. Therefore, although our results support the use of psychostimulants against the symptoms of ADHD in preschool children, further studies are still needed to provide more tangible evidence.With respect to our primary outcomes, our findings in support of the therapeutic efficacy of psychostimulants for both core symptoms of ADHD  as well as the global symptoms of ADHD indicated that the use of psychostimulants may improve not only the core symptoms of ADHD but also the general behaviors of ADHD children. Nevertheless, sensitivity analysis revealed a loss of significant therapeutic effectiveness against the symptoms of inattention from parents’ observation, the symptoms of inattention from teachers’ observation, and the symptoms of hyperactivity/Impulsivity from teachers’ observation after removal of the trial by Greenhill , suggestDespite our finding of moderate treatment efficacy regarding the use of psychostimulants for treating the symptoms of hyperactivity/impulsivity, the effect size was small for the symptom of inattention. Because the symptoms of hyperactivity/impulsivity among preschool children are school teachers’ major concerns that can be readily identified , under-rOur meta-regression further showed that age and gender differences were both associated with the treatment efficacy of psychostimulants against the global symptoms of ADHD. Taking into account that the higher prevalence of hyperactivity and behavioral disturbances among male ADHD children than among their female counterparts in classes , behavioSafety issues and potential adverse effects were the most important concerns regarding the use of psychostimulants in preschool children . LimitedThere are several limitations in the present meta-analysis. First, the inclusion of only nine RCTs with 544 participants may preclude an accurate assessment of studies outcomes. In particular, given the limited number of included trials, publication bias was assessed only by visual inspection of the funnel plot rather than analyzed by Egger’s test. In addition, imprecisions and inconsistencies of study results together with the small sample sizes may contribute to the low to very low qualities of evidence derived from the current meta-analysis. Moreover, our sensitivity analysis further revealed a significant impact of one study  on the oIn summary, our results supported the effectiveness of psychostimulants against the symptoms of ADHD in preschool children, especially for hyperactivity/impulsivity from teachers’ observation. Better therapeutic effects of psychostimulants were observed in those with an older age, male gender, and a longer duration of treatment. Psychostimulants also seemed to have tolerable side effect profiles for most preschool children. However, given the risks of potentially severe adverse effects and limited quality of the current evidence, more research is warranted to support their use in this age group.


The neuro-developmental deficits of Attention-Deficit Hyperactivity Disorder (ADHD) including decreased attention span, hyperactivity, distractibility, and impulsivity are frequently observed in children, adolescents and adults with a range of conditions , Cochran et al. report (n = 734), contrary to previous studies, that maternal smoking during pregnancy and pregnancy associated hypertension are did not predict ADHD at 10 and/or 15 years.In the ELGAN Study sample of children born at extremely low gestational age , more than double the prevalence of ADHD in otherwise healthy pediatric populations, highlighting that the negative influence on neuropsychiatric functioning likely begins sooner in the disease course than previously anticipated. The authors propose these findings are of large practical importance as ADHD symptoms are likely to impact routine everyday decisions crucial for diabetes management .Several studies in this issue describe specific aspects of ADHD and ADHD “symptoms” in chronic pediatric conditions. Duquette et al. describe ADHD in children with Chronic Kidney Disease (CKD). Although the sample size was small, results from the current study provide some of the most comprehensive findings to date on the differential attention functioning of children with CKD. Taken together, these findings suggest the existence of specific types of attention dysfunction, particularly in the focus/execute, sustain, and encoding, components of attention .Uliel-Sibony et al. provide a comprehensive literature review of the common co-occurrence of ADHD and epilepsy, and describe the latest research regarding possible etiologies explaining the common co-occurrence. This review looks at the influence of medications on both disorders and the recommended treatment approaches in accordance with the latest literature .Sabag and Geva provide a neurobiological perspective on the very significant comorbidity of attention in autism spectrum disorder (ASD), describing the framework of attention network activation in ASD, and suggesting that this neurobiological perspective be considered for further investigation in naturalistic settings.Slobodin and Davidovitch highlight the associations and differences between children's self-reports, parents' and teachers' reports, and standardized continuous performance test (CPT) data, and discuss the clinical and ethical imperative of taking children's perspectives into account during ADHD diagnosis and treatment.Dakwar-Kawar et al. providing initial support for the efficacy of this combined method in improving processing speed in the presence of mental fatigue in pediatric ADHD.Novel treatment approach of trans-cranial electric stimulation combined with cognitive training is described by Dutta et al. complete the series with a bottom-up holistic approach to the psychopharmacology of ADHD in the context of recent models of attention and suggest that future studies are greatly needed to better appreciate the interactions among an ADHD diagnosis, stimulant treatment across the lifespan, and structure-function alterations in the aging brain.We hope this Research Topic will update our readers on both research and clinical aspects of ADHD.IB, AL, and YL conceptualized and conducted the project, collected the study data, drafted the manuscript, and reviewed the final manuscript. All authors have read and approved the final manuscript.


Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral disorder characterized by inattention, hyperactivity, and impulsivity. Sport and physical activity have been shown to play a major role in the development of cognition, memory, selective attention, and motor reaction time, especially among adolescents with ADHD. In this context, the objective of this study was to investigate the effects of a swimming exercise program on the symptoms of ADHD in an adult with a diagnosis since childhood. The training intervention was performed for eight weeks, and the results demonstrated that the swimming–learning program significantly alleviated the symptoms of inattention and hyperactivity, as measured by the psychometric indices used in the study. Further studies are needed to establish and understand the association between physical activities and improved mental performance in adults with ADHD. Attention deficit hyperactivity disorder (ADHD) is a neurobehavioral disorder that typically emerges during childhood, with prevalence estimates ranging from 2 to 18% globally and three times higher in males than females . MoreoveADHD is characterized by three primary behavioral symptoms: (i) inattention, (ii) hyperactivity, and (iii) impulsivity . This diCurrent treatments for ADHD include pharmacological, psychotherapeutic, and psychoeducational interventions . NazarovPhysical activity has been extensively studied in children with ADHD and has shown positive effects on cognitive performance, ADHD symptoms, motor abilities, mental health, cognitive functioning, and motor coordination. The mechanisms underlying the beneficial effects of exercise are attributed to increases in arousal and catecholamine levels. These mechanisms are associated with the functioning of the prefrontal cortex, which could explain why executive functions appear to benefit more from exercise compared to other cognitive functions. Additionally, there is evidence suggesting that exercise leads to increases in cerebral blood flow (CBF), potentially affecting prefrontal brain regions or overall CBF ,11,12,13However, there is a limited body of research investigating the impact of physical activity, specifically in adults with ADHD. Nevertheless, existing studies suggest that even a single session of exercise can have positive effects on adult patients with ADHD .Swimming is an aerobic-based activity that allows people to develop good coordination, as it requires synchronized movements with their arms and legs while providing psychological benefits . Both chHattabi et al.  and SilvDespite the positive conclusions regarding the effectiveness of swimming in reducing ADHD symptoms, the literature still lacks studies conducted on adult cohorts. Therefore, within this theoretical framework, the aim of the present case study was to examine the influence of an aerobic type of physical activity on ADHD symptoms. More specifically, an intensive swimming training program was designed with the goal of potentially alleviating ADHD symptoms and enabling a 31-year-old female to effectively handle her workplace responsibilities.2) experiencing difficulties in concentrating and maintaining attention on tasks of her job and daily routine activities such as house cleaning, cooking, etc. More specifically, she had forgotten to close the oven in the kitchen while she was trying to solve a problem with the placement of the dishes in the cupboard. This situation made her nervous, and as a result, she felt depressed and unsuitable to deal with this.The subject of this case study was a 31-year-old woman  for adults , indicatDuring the study, she was working as a nurse; hence, the symptoms manifested more frequently at the workplace and in intense, stressful, and emotional situations. On the contrary, no such symptoms were observed when the patient engaged in activities she enjoyed, such as long-distance running.The patient followed an intense swimming training program for eight consecutive weeks, from 10 October to 9 December 2022, with three swimming and two dryland training sessions per week. It was held on Monday, Wednesday, and Friday from 9:00 a.m. to 12:00 p.m. to avoid the circadian rhythm problem . Each seAs the individual did not know how to swim before the intervention, the instruction started with simple tasks such as head immersion and exhalation under the water, flutter kicks in the front and supine position, etc. Then, the different hand strokes and swimming styles were taught and practiced. Also, the burden of the activity was increased by combining different swimming strokes and increasing its total training volume.In addition, each new technique was introduced once the previous one had become a subconscious movement through repetition. Staying focused, memorizing the details of the technique, and practicing helped the patient achieve the goals of each training session. Moreover, the two dryland sessions included swimming technique drills, enhancing her ability to understand the drills in swimming sessions. The volume of each exercise repetition was 25 m, while the sets per exercise varied from four to six. The content of the drills is presented in While participating in this sport, she discovered that her ADHD symptoms were more manageable, and she attributed this to her rigorous exercise routine. However, after the eight-week intervention, she was forced to discontinue the sport due to an injury. As a result, she experienced an increase in ADHD symptoms, which significantly impacted the quality of her work.The patient underwent evaluation using the following validated psychometric scales after obtaining informed consent: (i) the Beck Depression Inventory (BDI-II), (ii) the Barratt Impulsiveness Scale (BIS-11) , and ii is a selThe HADS-14  Supplem is also The patient’s psychometric tests showed a significant percentage reduction. Specifically, BDI-II scores, prior to the intervention until immediately after it, dropped from mild depression to normal, respectively, showing a 100% reduction. Also, the BIS-11 score decreased by almost 50% compared to the beginning of the intervention, indicating an individual that is extremely over-controlled. Concluding, the score in HADS-14 revealed that the patient, from a situation highly likely for a mental disorder, reached a lack of it at the end of the intervention with a reduction near 33% .The aim of the present case study was to investigate the effect of swimming, a closed motor skills sport, on the symptoms of ADHD in an adult who had been diagnosed with the condition since childhood and was not taking any medication. It is generally well-established that closed motor skills are beneficial for hyperactive/impulsive symptoms, while open motor skills are beneficial for attention problems .According to our results, it was found that the psychological condition of the subject improved during and after the exercise program. In fact, her scores on all three psychometric scales  used depleted to levels indicative of someone with no ADHD, demonstrating a decrement from 33 to 100%. Ahmadi et al.  showed tDifferent results were observed in the BIS-11 scores compared to the literature. Specifically, in our case report, the participant significantly reduced her scores at the end of the exercise intervention from 57 to 27. Lee et al.  showed tLast but not least, the HADS-14 scores decreased during and after the intervention program, indicating a lower depression and anxiety profile. Similarly, de Oliveira et al.  demonstrRegarding the participant’s personality, her dedication to focusing on the required tasks and her commitment to practicing diligently to achieve her goal of learning to swim and training as a long-distance swimmer contributed to her successful performance in her professional responsibilities as a nurse. Furthermore, as reported by the participant, engaging in physical activity helped alleviate her intense ADHD symptoms and deal with her professional responsibilities more effectively.In particular, the patient approached swimming training not just as a hobby but as a form of therapy to help manage her ADHD symptoms. This decision was based on her previous experience with sports, where engaging in vigorous physical activities during childhood had proven beneficial in controlling her ADHD symptoms. Therefore, it is plausible that a closed motor skill activity like swimming can have positive effects on ADHD symptoms like hyperactivity/impulsiveness, confirming the literature . AdditioPerhaps the repeatability of movements involved in closed motor skills, such as swimming, can be beneficial for ADHD patients. These skills provide precise movements that are repeatedly practiced, making them easier to learn and concentrate on specific stuff. Open motor skills, on the other hand, may be more challenging for patients due to the requirement of multiple movements, which can lead to confusion and distraction. Therefore, our finding presents another point for discussion and a perspective that warrants exploration.In our case, the patient’s questionnaire scores indicated an improvement in her mental health. Furthermore, by observing her swimming ability and reported behavior, it was assumed that this swimming intervention had a positive influence on cognitive functioning, motor coordination, and physical fitness. However, it is challenging to generalize our results due to the necessity of larger cohorts in order to assess the impact of swimming activity on ADHD.Considering the literature, it is indicated that physical activity has a positive impact on mental health, cognitive functioning, motor coordination, and physical fitness in individuals with ADHD  as well An eight-week vigorous swimming intervention appears to alleviate symptoms of inattention and hyperactivity on all three psychometric scales, BDI-II, BIS-11, and HADS-14, improving the mental health of a 31-year-old female patient. However, based on the limitations of our study, it is concluded that further intervention studies are needed to establish and understand the association between physical activities and improved mental performance in larger adult cohorts with ADHD, utilizing more psychometric and performance measurements.In the present case, the intervention of an ADHD adult patient was not found in any other study. Thus, the evaluation of mental health and the observation of her behavior is novel. Despite this, there are some limitations in the study that probably affect the results.We required additional measurements related to physical performance and cognitive function. The reason behind this decision was to minimize disturbances and potential anxiety that these tests could cause by using a reduced number of measurements;We did not use the BIS-11 questionnaire in the middle measurement of the intervention because she was not in the mental condition to answer all the questions. Therefore, we avoided putting pressure on her.


Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder that occurs in early childhood and can persist to adulthood. It can affect many aspects of a patient's daily life, so it is necessary to explore the mechanism and pathological alterations. For this purpose, we applied induced pluripotent stem cell (iPSC)-derived telencephalon organoids to recapitulate the alterations occurring in the early cerebral cortex of ADHD patients. We found that telencephalon organoids of ADHD showed less growth of layer structures than control-derived organoids. On day 35 of differentiation, the thinner cortex layer structures of ADHD-derived organoids contained more neurons than those of control-derived organoids. Furthermore, ADHD-derived organoids showed a decrease in cell proliferation during development from day 35 to 56. On day 56 of differentiation, there was a significant difference in the proportion of symmetric and asymmetric cell division between the ADHD and control groups. In addition, we observed increased cell apoptosis in ADHD during early development. These results show alterations in the characteristics of neural stem cells and the formation of layer structures, which might indicate key roles in the pathogenesis of ADHD. Our organoids exhibit the cortical developmental alterations observed in neuroimaging studies, providing an experimental foundation for understanding the pathological mechanisms of ADHD.The online version contains supplementary material available at 10.1007/s12015-023-10519-z. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder mainly characterized by symptoms of inattention, impulsivity, and hyperactivity. The symptoms can be observed from early childhood and often persist to adulthood , 2. ThisThe symptoms of ADHD are associated with a combination of clinical, neurodevelopmental and cognitive factors, all of which are based on distinct neuroanatomical foundations . PreviouAlthough prenatal neurodevelopment and postnatal neuroplasticity are considered to be inextricably linked to the pathophysiology of psychiatric disorders, including ADHD , poor achttp://chromocenter.com/) and confirmed that there were no abnormal chromosomes in the iPSCs of the ADHD patient  and sliced into 10 µm thick sections. The sliced tissues were transferred to CREST-coated glass slides (Matsunami Glass). Slides were washed with PBS, permeabilized with 0.3% Triton X-100 for 10 min, and blocked with 10% normal donkey serum in 0.3% Triton X-100/PBS for 30 min, followed by incubation with primary antibody overnight at 4℃. Primary antibodies against the following antigens were used at the specified dilutions: FOXG1 , TUJ1 , SOX2 , CTIP2 , TBR1 , phospho-histone H3 , cleaved caspase 3 , and Ki67 . Fluorescence-tagged secondary antibodies (Jackson) were reacted on the following day. The nuclei were counterstained with DAPI .The morphology of sliced tissues was measured using ImageJ (NIH). Cortical structures with diameters less than 200 µm were excluded from measurement. All data are presented as the mean ± standard deviation (S.D.). Statistical analyses were performed using GraphPad Prism software version 9 . For multiple comparisons, the Kruskal‒Wallis test was used followed by a post hoc test. The chi-square test was used for contingency table analyses. A p value < 0.05 was considered to be statistically significant.Next, we used iPSCs from ADHD and control individuals to generate telencephalon organoids. After 35 days of differentiation (day 35), cell aggregates expressed FOXG1, a specific marker of the telencephalon , whereas the NE of ADHD-derived organoids was thinner than that of control-derived organoids on day 56 (p < 0.001). Moreover, although the thickness of the NE of control-derived organoids was significantly increased between day 35 and 56 (p < 0.001), that of ADHD-derived organoids showed no significant change.To distinguish morphological changes occurring in the early cortex in ADHD, we measured the thickness of layer structures in the telencephalon organoids Fig. c. The thp < 0.05; day 56: p < 0.001, Fig. p > 0.05, Fig. p < 0.01). In the comparison of the thickness between day 35 and 56, the thickness of the CP was significantly increased in both control- and ADHD-derived organoids , whereas the VZ of ADHD-derived organoids was not significantly increased between day 35 and 56. These results suggested that the CP of ADHD-derived organoids, the cerebral cortex in early development, was thinner than that of control-derived organoids, possibly due to the alteration in the growth of the VZ, the layer of neural stem cells.Next, we analyzed the thickness of the CP contained in the NE and found that the CP of ADHD-derived organoids was thinner than that of control-derived organoids on both day 35 and day 56 , whereas no significant increase was observed in ADHD-derived organoids. These results showed altered growth of the early cortex, meaning that an increase in the number of neurons was disrupted in ADHD-derived organoids.For further analysis of morphological differences, we counted the number of cells expressing TBR1 and/or CTIP2, specific marker proteins of neurons in layer VI and V of the cerebral cortex , suggesting less potential to proliferate.Our morphological analysis showed that ADHD-derived organoids had a thinner layer structure than control-derived organoids, even though there were more neurons in the layers than in the control-derived organoids. This suggested that alterations occurred in the neurodevelopment of ADHD-derived organoids, including division of neural stem cells, differentiation from neural stem cells into neurons, and apoptosis of the cells. For further investigation, we counted the number of cell divisions indicated by the expression of phospho-histone H3 , with an increase in asymmetric division and a decrease in symmetric division. On day 56, the proportion of symmetric and asymmetric division showed a significant difference in control- and ADHD-derived organoids : control-derived organoids showed more asymmetric division and less symmetric division than ADHD-derived organoids. These results suggested that the proportion of cell division gradually shifted from proliferation to differentiation in a relatively later stage of development in control-derived organoids but not in ADHD-derived organoids.Furthermore, we analyzed the proportion of symmetric and asymmetric cell division: cell division for the proliferation of neural stem cells and differentiation from neural stem cells into neurons , 27. Whep > 0.05, Fig. p < 0.05; ADHD: p < 0.001, Fig. p < 0.01). These results indicated two characteristics of ADHD cells: the amount of cell proliferation was decreased in early development, and much apoptosis occurred. Alterations in proliferation and apoptosis might drive the changes in the morphology of layer structures and the number of neurons.Finally, we distinguished possible changes in cell death. We analyzed the amount of cleaved-caspase 3 (CC3) and Ki67, the marker protein for apoptosis and proliferation of cells Fig. a. In conIn the present study, we differentiated iPSCs derived from an ADHD individual into telencephalon organoids. During early neurodevelopment, the early cortex in the organoids had thin layer structures accompanied by poor growth of the NE and VZ. Although the CP of ADHD-derived organoids was thin, it contained more neurons than the control in the early developmental stage, and the number of neurons showed a poor increase in the following stage. ADHD-derived organoids also showed decreased cell division, an altered proportion of proliferation and differentiation, and increased apoptosis in the early developmental stage. Our biological models could reflect altered cortical neurodevelopment in ADHD-derived organoids at the same developmental stage in vivo –30.Brain imaging has been used to characterize the neurobiological basis of ADHD, especially the morphology of the frontal lobes. However, the symptoms of ADHD and the delay in the morphological development of the cerebral cortex are continuously altered during maturation , 31. TheThe regulatory effects of ADHD susceptibility genes on neural differentiation are mainly manifested in neuronal proliferation, migration, synaptic formation and synaptic plasticity , 39. RegAnother finding we would like to discuss is the small size of neurons in ADHD, which was indicated by the findings that the CP of ADHD-derived organoids contained more neurons in the thinner layer than those in control-derived organoids. Neurodevelopmental abnormalities in the prefrontal cortex of animal models of ADHD, such as fewer branch points and roots, shorter neurite length in spontaneously hypertensive rats –42, and Another important finding is the alteration in the proportion of proliferation and differentiation of neural stem cells, which play a crucial role in cortex development. Neural stem cells renew themselves and differentiate into neurons through symmetric and asymmetric cell division, and this proper balance maintains increase and growth of neurons –46. NeurThese findings may be limited in part because the three iPSC lines that we used to differentiate into the organoids were derived from the same individual. Samples derived from more individuals will provide more possibilities for the establishment and comparison of organoids and can also expand the pathological analysis of ADHD.Our in vitro models demonstrate the possible contribution of neural proliferation and differentiation and apoptosis in the formation of the early cortex and suggest the possible mechanisms of delayed cortical maturation in ADHD patients. These results show the alterations in the characteristics of neural stem cells and the formation of layer structures, potentially indicating key players in the pathogenesis of ADHD.Supplementary Fig. 1.Induction of iPS cells from an ADHD patient. The three iPS cell lines  were generated from the same patient. (a) Immunocytochemistry for Nanog, OCT3/4, SOX2, SSEA4, and TRA-1-60. Scale bars: 100 μm. (b) Embryoid body–mediated differentiation of human iPS cells. Immunocytochemistry of TUJ1, α-smooth muscle actin (α-SMA) and α-fetoprotein (AFP). Scale bars: 200 μm (PNG 1148 kb)High resolution image (TIF 7.92 MB)Supplementary Fig. 2.Cytogenetic analysis of the cultured iPS cells by Q-banding (PNG 856 kb)High resolution image (TIF 3.25 MB)Supplementary Fig. 3.Time schedule of telencephalon organoid generation (PNG 192 kb)High resolution image (TIF 1.05 MB)


M = 15.58, SD = 1.71) completed the Global Assessment of Internet Trolling-Revised, Adolescent Measure of Empathy and Sympathy, Rosenberg Self-Esteem Scale, Youth Psychopathy Traits Inventory-Short Version, Social Rewards Questionnaire, Short Sadistic Impulse Scale, and a series of questions related to the experience of trolling. Results showed in the past year, 24.2% of Australian adolescents reported being trolled and 13.4% reported having trolled others. Gender, psychopathy, sadism, self-esteem, cognitive empathy, affective empathy, and “negative social potency”  combined, explained 30.7% of variance in adolescents’ trolling behaviours (p < .001). When accounting for shared variance, gender , high psychopathy, and high negative social potency were significant predictors of trolling, aligning with findings of adult samples. Contrary to adult samples, sadism was not a unique predictor of adolescents’ trolling. For adolescents, the variance in trolling explained by sadism was nonsignificant when controlling for negative social potency. These similarities, and differences, in predictors of trolling across adult and adolescent samples may play a critical role in the development of targeted interventions to prevent or manage trolling.To understand why people “troll” , researchers have explored a range of individual differences. These studies have primarily been conducted in adult samples, despite adolescents being a particularly vulnerable group with regards to both being trolled and trolling others. In this study we aimed to (1) explore Australian adolescents’ experiences of trolling, and (2) replicate adult research that has constructed a psychological profile of the Internet troll by examining the utility of personality traits (psychopathy and sadism), self-esteem, empathy (cognitive and affective), and social rewards  to predict adolescents’ trolling behaviours. A sample of 157 Australian adolescents  aged 13–18 years ( Social media use has a range of benefits for adolescents, including opportunities for learning and entertainment , peer coBroadly, trolling has been adopted as an umbrella term to describe a range of antisocial deviant online behaviours . In the Australian Online Safety Act 2021) strengthening existing online safety laws. Targets of trolling report experiencing negative psychological consequences such as distress and lower self-esteem [Online behaviours that characterise trolling are increasingly common; for example, The Australia Institute reported that 39% of the adult population have experienced online harassment . It is af-esteem , and incf-esteem . The potf-esteem .Adolescence is a significant biological, social, and psychological developmental period . During Social media provide social, educational, and mental health benefits to adolescents –3; howevPrevious multi-disciplinary research exploring predominantly adult populations has linked certain personality traits with trolling , 29, 30.Psychopathy is characterised by diminished empathy, impulsivity, thrill-seeking , interpeNonclinical sadism is characterised by the enjoyment of causing others harm, and those with high sadism manipulate others using fear and intimidation . IndividSeveral other factors have also been implicated as potentially playing a role in trolling behaviours. In adult samples, low self-esteem has been related to increased trolling incidence , 13. TheIn addition to self-esteem, empathy has been associated with perpetration of trolling behaviours in a sample of adults  and may high perspective taking was associated with increased bullying for girls, with no relationship for empathy concern [To theorise the role that empathy may play in adolescents’ who troll, we draw on the extant literature exploring adolescents’ empathy and other antisocial behaviour. In children and adolescent samples, low cognitive and affective empathy have been linked to increased incidence of bullying, with the magnitude of effect stronger for affective empathy . Compara concern . A lack  concern , and ado concern .Although limited research has explored the role of cognitive empathy in antisocial online behaviour, we can extrapolate from studies exploring emotional intelligence to understand the role of cognitive empathy. Like cognitive empathy, emotional intelligence is defined as the ability to perceive, recognise, understand, and express others’ emotions . EmotionA final theoretical and developmental perspective of importance is adolescents’ attunement to social interactions, that is theorised to increase their sensitivity to social rewards . CallousIn the current study, we aimed to explore adolescents’ experience of trolling, including how often they are trolled and how often they troll others. Further, we aimed to explore the psychological profile of adolescents who troll, specifically, by examining the utility of personality traits , self-esteem, empathy (cognitive and affective), and social rewards  to predict trolling in a sample of Australian adolescents. Given the lack of research on trolling and adolescents, this nature of this study is somewhat exploratory. Still, based on previous results in adult samples, we hypothesise that for adolescents, high psychopathy, high sadism, low self-esteem, low cognitive empathy, low affective empathy, and high negative social potency will predict more trolling. By identifying the potential characteristics and profile of adolescents who troll, we aim to inform the development of intervention and prevention strategies to reduce the impact of antisocial online behaviours.SD = 1.71). Of participants, 64 (40.8%) identified as male, 91 (58%) identified as female, and 1 (0.6%) identified as non-binary (1 participant did not respond).A total of 157 Australian adolescents completed the study. Participants were aged 13–18 years old with an average age of 15.58 years  was included in the current study to assess participants’ trolling behaviours. Minor changes in the wording of two items were made to better align with an adolescent sample. The GAIT-R is comprised of 8 self-report items  and participants respond to items on a 5-point Likert scale . One item is reverse scored. After recoding, responses are summed for total scores with higher scores indicating more trolling behaviours.Participants were provided with an operational definition of Trolling and asked to respond on a dichotomous “yes/no” scale to “During the past year, did anyone ever troll you on the Internet?”. The operational definition read:Trolling is internet slang for a person who intentionally starts arguments or upsets others by posting comments that will get a reaction. These people are referred to as “trolls”. Trolls like to provoke and upset other people online, with the intention to cause some harm. A troll might leave rude comments in a public comment section, with the purpose of grabbing the attention of other visitors and disrupting the discussion that would otherwise be about the page’s content. The comments might include content that is hateful, racist, sexist, or disrespectful.A “yes” response further prompted participants “How many different times did someone troll you on the Internet in the last year ?” with response options ranging from “1” to “6 or more”. Participants then responded on the same scale as outlined above about their experience of engaging in the behaviour . The format of these items was based on the Bullying and Cyberbullying Scale for Adolescents .The AMES was included to measure adolescents cognitive and affective empathy. The AMES also includes a subscale of sympathy, however, this was not included in the current study. The cognitive empathy subscale (α = .83) includes four items  and the affective empathy subscale (α = .80) includes four items . Participants respond on a 5-point Likert scale . Responses are summed for total scores with higher scores indicating higher levels of empathy.The RSES (α = .86) was used to measure adolescent global self-esteem. Participants respond to 10 self-report items  on a 4-point Likert scale . Five items are reverse scored and after recoding, responses are summed for total scores with higher scores indicating higher levels of overall self-esteem.Adolescents’ psychopathy was assessed with the YPI-S (α = .86), an 18-item self-report measure. The YPI-S includes three subscales (dimensions) of psychopathy: Interpersonal , affective , and behavioural . Respondents indicate how strongly statements apply to them on a 4-point Likert scale . Responses to subscales are summed for a total score.The negative social potency subscale (α = .84) of the SRQ was included to measure the degree adolescents experienced reward when engaging in antisocial interpersonal interactions . The subscale includes 5 items  and participants respond to items on a 6-point Likert scale . Responses are summed for total scores, with higher scores indicating higher negative social potency.The SSIS (α = .88) was used to measure adolescents’ level of everyday sadism. The SSIS is comprised of 10 self-report items  and participants indicate their agreement to items on a 5-point Likert scale . One item is reverse scored. After recoding, responses are summed for total scores with higher scores indicating higher levels of sadism.Ethical approval was granted by the University of Southern Queensland Human Research Ethics Committee with Approval No. H17REA260. Participants were recruited by advertising through social media accounts , first year undergraduate psychology courses at the authors’ institutions, and word of mouth. Phase 1 of recruitment also included contacting the principals of High Schools in the greater Brisbane and Toowoomba areas, requesting they share the advertisement in their School newsletters (or similar).Next button at the bottom of the page containing detailed information about the anonymous study. The Children’s Online Privacy Protection Act recommends children under the age of 13-years do not use social media applications. As the target cohort was older than this, and able to use social media, in addition to the low-risk nature of the study, parental permission was not obtained for participants before joining the study. Although not anticipated, to minimise any risks of participation in the project, information and contact details were included at the bottom on each survey page in case the issues raised in the questionnaire created uncomfortable or distressing feelings. Participants could also choose to withdraw at any time during the study prior to the final submission page by not submitting the survey or closing their browser. After consent was provided, the study became accessible. Tips promoting online safety were included on the final page of the survey. Completion of the survey in its entirety took approximately 30 minutes.Inclusion criteria for participation was age (between 13–18 years) and that social media was used in a typical week. The link in the study advertisement directed participants to details of the study. Written consent was obtained from all adolescent participants by clicking the st June, 2021 and 26th July, 2021. During this phase, participants were given the option of entering a draw to win one of 10 Ultimate Student gift cards valued at $50  or receive course credit (if enrolled in an eligible university course). Once participants completed the study, they were directed to a second, unlinked survey  to enter their email (Phase 1) or postal (Phases 2 and 3) address, for the draw, or provide the relevant details for course credit. Phase 1 resulted in the recruitment of 68 participants.There were three phases of recruitment. Each phase included the same recruitment process excluding incentives offered for participation, and the contacting of School principals (isolated to Phase 1). Phase 1 took place between 1nd August, 2021 and 8th September, 2021 and resulted in the recruitment of 46 participants. Phase 3 took place between 13th June, 2022 and 15th August, 2022 and resulted in the recruitment of 45 participants. Phase 3 was unplanned but necessary to increase the sample size after detailed data screening of Phases 1 and 2 indicated the likely presence of bot generated data  was included in Phase 3.2 deviation from zero) with power at .95, an effect size of .15, and alpha at .05, indicated a sample size of 153 was required for adequate power and this was satisfied.The study was a correlational, cross-sectional design with the predictor variables of psychopathy, sadism, self-esteem, cognitive empathy, affective empathy, and negative social potency. The criterion was trolling (as measured by the GAIT). Following guidelines of previous studies , 58, genBased on the operational definition of trolling provided, 24.2% of participants indicated they had been trolled in the previous year (by gender 28.1% boys and 19.8% of girls), and 13.4% of participants indicated they had trolled others in the previous year (by gender 28.1% of boys and 3.3% of girls). A frequency table for adolescents who had been trolled and who had trolled others can be seen in Supplementary analyses using the descriptive trolling data is presented in Descriptives  can be seen in As can be seen in 2 adjusted) of variance in trolling, R2 = .08, F = 12.45, p < .001. At step 2, psychopathy, sadism, self-esteem, cognitive empathy, affective empathy, and negative social potency explained an additional significant 26.3% (R2 change) of variance in trolling, and this change was significant, Fchange = 9.74, p < .001. As a total model, the variables explained a significant 30.7% (R2 adjusted) of variance in trolling, R2 = .34, F = 10.73, p < .001, with a large effect size of ƒ2 = .52. Coefficients are presented in A 2-Step Hierarchical Multiple Regression Analysis was run to predict trolling with gender entered at Step 1 and psychopathy, sadism, self-esteem, cognitive empathy, affective empathy, and negative social potency entered at Step 2. At step 1, gender explained a significant 6.9% (Rr2 = 27%) and sadism and negative social potency (r2 = 49%) was captured in the regression model, rendering sadism a nonsignificant predictor of trolling. To test this speculation, we ran two partial correlations between sadism and trolling controlling for psychopathy and negative social potency, respectively. When controlling for psychopathy, sadism and trolling still shared a significant, positive correlation, r(154) = .21, p = .009, however, when controlling for negative social potency, sadism and trolling were no longer correlated, r(154) = .02, p = .762.As can be seen in In the current study, we explored adolescents’ experience of trolling, including how often they are trolled and how often they troll others. Further, we aimed to replicate adult research that has constructed a psychological profile of the Internet troll by exploring the utility of personality traits (psychopathy and sadism), self-esteem, empathy (cognitive and affective), and social rewards  to predict perpetration of trolling in a sample of Australian adolescents. We predicted that high psychopathy, high sadism, low self-esteem, low cognitive empathy, low affective empathy, and high negative social potency would predict more trolling, and results supported this hypothesis.We documented the frequency that Australian adolescents reported both being trolled and having trolled others. This documentation is a particularly novel contribution of the current study, as we provided adolescents with an operational definition of trolling, which has not previously occurred. Given the discrepancies that exist regarding defining trolling amongst both researchers and the general population , 65, by The rates of trolling experienced by Australian adolescents in this sample are similar, albeit slightly higher, than the experience of cyberbullying, as recent reports show approximately 20% of Australian adolescents experience cyberbullying . AlthougWe found that the most popular social media platforms used by participants were Instagram (77.1%), YouTube (71.3%), and Snapchat (65.6%), a finding consistent with recent research . While wIn adult samples, psychopathy, sadism, self-esteem, empathy, and negative social potency have all demonstrated relationships with trolling. In this study, these constructs, plus gender, cognitive empathy, and affective empathy, explained 30.7% of variance in adolescents’ trolling. When examining the specific predictors, there was some replicability of previous findings regarding predictors of trolling in adult sample; however, also some notable differences.We found that for adolescents, high psychopathy both correlated with and uniquely predicted increased incidence of trolling. This finding is consistent with results of adult samples , 13, 30,Also similar to adult samples , 58, higAdolescents’ sadism was a significant, positive correlate of trolling behaviours—a finding also consistent with adult samples , 41, 58.In the current study, adolescents’ cognitive empathy was a significant, negative correlate of trolling behaviours. Affective empathy was not correlated with trolling, and neither dimension of empathy emerged as a unique predictor of adolescents’ trolling in the shared variance model. This pattern of results for empathy and trolling appears qualitatively different to adults who troll, as past research has shown adults’ cognitive empathy has no significant bivariate relationship with trolling, and adults with low levels of affective empathy more likely to troll . As the Unlike adult samples where self-esteem shares a negative bivariate relationship with trolling , self-esAlthough the variables of gender and age were not specific variables of interest, they warrant consideration. Similar to adult cohorts , 13, ageOf interest, a recent study found that compared to adolescent girls, adolescent boys who experienced cyberbullying increased their likelihood of cyberbullying others . A trollThe findings of this study indicate ongoing research, education, and skills training is necessary to better understand adolescents’ trolling. Given that the experience of trolling is associated with significant negative psychosocial outcomes for both the troll  and their target  and trolling. Qualitative research with adolescents regarding the experience of trolling would also be of value. More specifically, in-depth examinations of how trolling occurs, including victim-perpetrator responses, would greatly assist in understanding the antecedents that trigger the behaviour and the consequences that contribute to maintaining Internet trolling behaviours. Additionally, a longitudinal focus on studying adolescents over time would provide insight into the long-term effects of trolling, and for those adolescents who are also trolls, understanding on the evolution of a troll from adolescence to adulthood. This will also provide insight into additional areas for intervention, by highlighting where education strategies should be targeted and what skills are required of both the target and the “troll” to manage or halt the interaction.Given the complexity of trolling, we also recommend that future research consider exploring the intentions associated with trolling behaviour. For example, does the troll intend to entertain  or abusLastly, past research has shown that trolling behaviour in adults on social media is most common in posts involving politics or current events  and sociThe current study provides the first investigation of Australian adolescent’s experiences of trolling and factors associated with this behaviour. We were particularly interested in exploring individual differences, such as personality traits and empathy, that have been implicated in adults who troll. We have demonstrated similarities between adolescent and adult samples—specifically, for both age cohorts, gender, high psychopathy, and high negative social potency emerge as predictors of trolling. Our findings also demonstrate differences that may be key to understanding trolling behaviours across age cohorts. For adolescents, when sadism, psychopathy, and negative social potency were included in the shared variance model, sadism was no longer a predictor of trolling—a finding not observed in an adult sample . We discS1 Table(DOCX)Click here for additional data file.S2 Table(DOCX)Click here for additional data file.S1 Appendix(DOCX)Click here for additional data file.S2 Appendix(DOCX)Click here for additional data file.


The number of publications examining early markers of ADHD is rapidly growing  and clinical, developmental, and behavioral predictors acquired over the first 30 months of life in relation to later childhood ADHD, Tobarra‐Sanchez et al.  have takThe potential implications of this work for future research are numerous. For example, it highlights the pressing need for prospective studies from birth specifically designed to address questions about early markers of ADHD (despite known limitations of such designs). Large birth cohort studies provide invaluable information but, due to their nature, may rely more heavily on parent‐report metrics versus direct assessment and deep phenotyping, along with variable batteries across time. When used to address research questions that they were not necessarily intended to answer at the outset, some limitations are therefore imposed. In this case, data were acquired across multiple ages between 15 and 30 months and were not always simultaneously measured, likely resulting in a loss of developmental nuance. For example, hearing/vision concerns were assessed at 15 months, motor skills were assessed at 18 months, vocabulary and temperament were assessed at 24 months, and regulatory issues were evaluated at both 24 (feeding) and 30 (sleeping/crying) months; these data were pooled in multivariable models despite dramatic changes in development during this period. Indeed, development is particularly dynamic at such early ages, making it difficult to extrapolate precise developmental meaning or potential effects of developmental cascades. Prospective studies focused on early markers of ADHD will provide opportunities to build upon Tobarra‐Sanchez et al.’s  findingsdid predict ADHD outcomes, this study raises intriguing questions based upon what did not predict ADHD outcomes in the univariate models, or which did predict ADHD outcomes in univariate models but not once included in the multivariable model. This includes a range of pre‐ and perinatal variables , as well as child‐level behavioral variables including temperament‐based distractibility and regulatory problems , and developmental variables . This may suggest that downstream child‐level behavioral and developmental characteristics, in addition to genetic risk, are more influential than factors associated with the pre‐/perinatal periods. Alternatively, methodological decisions, particularly the approach of dichotomizing the majority of predictors in favor of clinical utility, could have resulted in a loss of nuance. Also informative to future investigations are the inter‐relations among predictors, particularly given the inclusion of the ADHD PRS. Notably, the ADHD PRS z‐score did not correlate with any variables other than those related to the core dimensions or diagnosis of ADHD , with one exception , suggesting some degree of specificity.Equally important to what The incorporation of genetic risk into multivariable models investigating early markers of ADHD is a key advancement and aligns with widely accepted theories about the development of psychopathology. Despite this, there are some limitations to the use of PRS. These have been described elsewhere Shaw, , but a kAs the authors note, it will be critical for future research to focus on synergistic interactions between predictors as well as non‐linear interactions. Specificity is also an open question. For example, given that delayed motor and language development are well‐documented predictors of other neurodevelopmental conditions  emphasizes the need for the field to go beyond individual predictors and begin to develop and test prognostic diagnostic models Larsson,  which ha emphasizMeghan Miller: Conceptualization; Writing − original draft.Meghan Miller reports no biomedical financial interests or potential conflicts of interest.