Altered White Matter Integrity at Illness Onset in Adolescents With a First Episode of Psychosis.

Background: Disruption in white matter integrity has been consistently observed in individuals with psychosis. However, whether such abnormalities are already present at illness onset or are related to downstream processes remains elusive. The study of adolescents with a recent onset of psychosis provides the opportunity to evaluate white matter integrity proximally to disease onset. Methods: Twenty-six adolescents (aged 15.9 ± 1.3 years) with a first episode of psychosis (FEP) (less than 6 months duration) were compared with 26 age and sex-matched healthy controls (HC) (16.8 ± 2 years). In participants with a FEP, clinical diagnoses were confirmed after a minimum of 1 year follow-up (main categories: schizophrenia, bipolar disorder, or schizoaffective disorder). Anatomical images and diffusion tensor sequences were acquired using a 1.5T scanner. Whole brain, voxel-wise group differences in fractional anisotropy (FA) were investigated between participants with a FEP and controls. Results: Relative to HC, FEP participants displayed decreased FA in the right posterior cingulate gyrus, encompassing the right superior and posterior corona radiata, and the right parahippocampal gyrus, including the cingulum and fornix. FEP patients showed no areas of increased FA relative to HC. The results remained significant after controlling for medication, cannabis use and intelligence. Conclusion: Our findings indicate that adolescents with recent onset of psychotic disorders show decreased white matter integrity in circuits implicated in cognitive functions and emotion regulation.

Visual memory improvement in adolescents at high risk for suicide who are receiving psychotherapy at a community clinic.

The current study aims to: 1) investigate cognitive differences among adolescents at risk for suicide versus healthy controls (HC) and 2) identify cognitive changes associated with response to psychotherapy among adolescents at high risk for suicide. Thirty-five adolescents at high risk for suicide (HR), and 14 HC adolescents were recruited. Clinical and cognitive assessments were conducted in both groups at baseline and 16 weeks later (after the patients completed psychotherapy). HR and HC adolescents were compared at baseline and at completion of the study. We also conducted further analysis by separating into two groups the HR adolescents who responded to psychotherapy (n=17) and those who did not (n=11). At baseline, the HR group had significantly lower performance on verbal memory and processing speed than the HC group. At week 16, HR adolescents performed as well as HC adolescents in all cognitive domains. Among patients, better performance on visual memory was observed in those who responded to psychotherapy compared to those who did not. We concluded that lower performance on verbal memory and processing speed may be associated with a high risk for suicide among adolescents. Improvement in visual memory might be related to a lower risk for suicide in adolescents.

Do Pregnancy-Induced Brain Changes Reverse? The Brain of a Mother Six Years after Parturition.

Neuroimaging researchers commonly assume that the brain of a mother is comparable to that of a nulliparous woman. However, pregnancy leads to pronounced gray matter volume reductions in the mother's brain, which have been associated with maternal attachment towards the baby. Beyond two years postpartum, no study has explored whether these brain changes are maintained or instead return to pre-pregnancy levels. The present study tested whether gray matter volume reductions detected in primiparous women are still present six years after parturition. Using data from a unique, prospective neuroimaging study, we compared the gray matter volume of 25 primiparous and 22 nulliparous women across three sessions: before conception (n = 25/22), during the first months of postpartum (n = 25/21), and at six years after parturition (n = 7/5). We found that most of the pregnancy-induced gray matter volume reductions persist six years after parturition (classifying women as having been pregnant or not with 91.67% of total accuracy). We also found that brain changes at six years postpartum are associated with measures of mother-to-infant attachment. These findings open the possibility that pregnancy-induced brain changes are permanent and encourage neuroimaging studies to routinely include pregnancy-related information as a relevant demographic variable.

Functional Impairment and Clinical Correlates in Adolescents with Bipolar Disorder Compared to Healthy Controls. A Case-control Study.

BACKGROUND: Evidence shows that most adolescents with bipolar disorder (BD) achieve syndromic recovery after being referred to specialized treatment. However, functional recovery is reached in less than 50% of those cases. METHOD: Descriptive cross-sectional case-control study, based on a clinical sample of 44 BD patients aged 12-19, matched by age and sex with 44 healthy controls (HC). Psychopathology was ascertained using the KSADS-PL, in addition to the clinical scales. Information about previous academic performance was included, as well as functional outcome based on the Children's Global Assessment Functioning Scale (CGAS). Previous exposure to stressful experiences was assessed using the Schedule for Stressful Life Events (SLES). All analyses were performed using either conditional or stepwise logistic regression models. RESULTS: Once they have become stabilized, and even after controlling for socio-demographic differences, BD patients were associated with lower levels of functionality [OR 0.65 (0.46, 0.93), p=0.02], and worse performance at school [OR 0.03 (0.01, 0.67), p=0.03] compared with HC. Persistent sub-syndromal psychosis showed the strongest negative correlation with functionality (rho=-0.65, -0.57 for BD and HC respectively; p<0.001). Although BD was associated with more stressful life events, this association did not remain significant in the multivariate models. LIMITATIONS: The small sample size limits our ability to detect differences between groups, and between BD subtypes. CONCLUSIONS: Even when early detection and intervention is provided, BD has a significant impact on functioning and academic performance. It is important to address persistent sub-threshold symptoms and to emphasize the social and rehabilitative components of treatment.

CONTEXTE: Les données probantes indiquent que la plupart des adolescents souffrant de trouble bipolaire (TB) obtiennent un rétablissement syndromique après avoir été adressés à un traitement spécialisé. Cependant, le rétablissement fonctionnel n'est réalisé que dans moins de 50 % de ces cas. MÉTHODE: Une étude cas-témoins transversale descriptive, basée sur un échantillon clinique de 44 patients de TB âgés de 12 à 19 ans, appariés selon l'âge et le sexe avec 44 témoins en santé (TS). La psychopathologie a été déterminée à l'aide de KSADS-PL, en plus des échelles cliniques. L'information sur le rendement scolaire antérieur était incluse de même que le résultat fonctionnel basé sur l'échelle d'évaluation globale du fonctionnement pour les enfants (CGAS). L'exposition précédente à des expériences stressantes a été évaluée à l'aide de l'échelle des événements stressants de la vie (SLES). Toutes les analyses ont été menées à l'aide de modèles de régression logistique conditionnelle ou séquentielle. RÉSULTATS: Une fois stabilisés, et même après contrôle des différences sociodémographiques, les patients de TB ont été associés à des niveaux plus faibles de fonctionnalité [RC 0,65 (0,46, 0,93), p = 0,02], et à un rendement scolaire plus mauvais [RC 0,03 (0,01, 0,67), p = 0,03] comparé aux TS. Une psychose sous-syndromale persistante présentait la corrélation négative la plus forte avec la fonctionnalité (rho =−0,65, −0,57 pour TB et TS respectivement; p < 0,001). Bien que le TB soit associé à des événements plus stressants, cette association ne demeurait pas significative dans les modèles multivariés. LIMITATIONS: La taille modeste de l'échantillon limite notre capacité de détecter les différences entre les groupes, et entre les sous-types de TB. CONCLUSIONS: Même lorsque la détection et l'intervention précoces sont fournies, le TB a un effet significatif sur le fonctionnement et sur le rendement scolaire. Il est important de prendre en compte les symptômes de sous-seuil persistants et de mettre l'accent sur les composantes sociale et de rétablissement du traitement.

Adapted Dialectical Behavior Therapy for Adolescents with a High Risk of Suicide in a Community Clinic: A Pragmatic Randomized Controlled Trial.

OBJECTIVE: This study is a pragmatic randomized controlled trial, which compares the effectiveness of an adapted form of Dialectical Behavior Therapy for Adolescents (DBT-A) and treatment as usual plus group sessions (TAU + GS) to reduce suicidal risk for adolescents in a community health mental clinic. METHOD: Thirty-five adolescents from a community outpatient clinic, with repetitive NSSI alone or with SA over the last 12 months and with current high suicide risk as assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS), were enrolled. Participants were randomly assigned to undergo either DBT-A (n = 18) or TAU + GT (n = 17) treatments over a 16-week period. Primary outcomes were the difference between NSSI and SA recorded during the first 4 weeks and the final 4 weeks of treatment. Secondary outcomes included changes in Children's Global Assessment Scale (C-GAS), Suicidal Ideation Questionnaire (SIQ-JR), and Beck Depression Inventory-II (BDI-II). RESULTS: Dialectical Behavior Therapy for Adolescents was more effective than TAU + GS at reducing NSSI, use of antipsychotics, and improving C-GAS. No SAs were reported in the two groups at the end of the treatment. Both treatments were equally effective in decreasing SIQ-JR and BDI-II scores. CONCLUSIONS: These findings support the feasibility and effectiveness of DBT-A for adolescents at high risk of suicide in community settings.

Presence of Distractor Improves Time Estimation Performance in an Adult ADHD Sample.

Objective: It is widely accepted that patients with ADHD exhibit greater susceptibility to distractors, especially during tasks with higher working memory load demands. However, no study to date has specifically measured the impact of distractors on timing functions, although these have consistently shown alterations in ADHD. In this investigation, we aimed to elucidate the neural mechanisms mediating distractor effects on timing functions. Method: We employed a time estimation functional magnetic resonance imaging (fMRI) paradigm including a distracting element in half of the trials in a sample of 21 patients with ADHD and 24 healthy controls. Results: As expected, the effect of the distractor was greater in ADHD patients, where it was associated with increased orbitofrontal activity compared with controls. Behaviorally, time estimation performance benefited from the presence of distractors in both groups. In turn, such improvement correlated with medial frontal and insular activity in the brain. Conclusion: These results suggest that distractors could be stimulating recruitment of frontal resources in ADHD, thus contributing to increase focus on the task.

Becoming a mother entails anatomical changes in the ventral striatum of the human brain that facilitate its responsiveness to offspring cues.

In mothers, offspring cues are associated with a powerful reinforcing value that motivates maternal care. Animal studies show that this is mediated by dopamine release into the nucleus accumbens, a core component of the brain's reward system located in the ventral striatum (VStr). The VStr is also known to respond to infant signals in human mothers. However, it is unknown whether pregnancy modifies the anatomy or functionality of this structure, and whether such modifications underlie its strong reactivity to offspring cues. Therefore, we analyzed structural and functional neuroimaging data from a unique pre-conception prospective cohort study involving first-time mothers investigated before and after their pregnancy as well as nulliparous control women scanned at similar time intervals. First, we delineated the anatomy of the VStr in each subject's neuroanatomical space and examined whether there are volumetric changes in this structure across sessions. Then, we tested if these changes could predict the mothers' brain responses to visual stimuli of their infants. We found decreases in the right VStr and a trend for left VStr reductions in the women who were pregnant between sessions compared to the women who were not. Furthermore, VStr volume reductions across pregnancy were associated with infant-related VStr responses in the postpartum period, with stronger volume decreases predicting stronger functional activation to offspring cues. These findings provide the first indications that the transition to motherhood renders anatomical adaptations in the VStr that promote the strong responsiveness of a mother's reward circuit to cues of her infant.

Stepwise functional connectivity reveals altered sensory-multimodal integration in medication-naïve adults with attention deficit hyperactivity disorder.

Neuroimaging studies indicate that children with attention-deficit/hyperactivity disorder (ADHD) present alterations in several functional networks of the sensation-to-cognition spectrum. These alterations include functional overconnectivity within sensory regions and underconnectivity between sensory regions and neural hubs supporting higher order cognitive functions. Today, it is unknown whether this same pattern of alterations persists in adult patients with ADHD who had never been medicated for their condition. The aim of the present study was to assess whether medication-naïve adults with ADHD presented alterations in functional networks of the sensation-to-cognition spectrum. Thirty-one medication-naïve adults with ADHD and twenty-two healthy adults underwent resting-state functional magnetic resonance imaging (rs-fMRI). Stepwise functional connectivity (SFC) was used to characterize the pattern of functional connectivity between sensory seed regions and the rest of the brain at direct, short, intermediate, and long functional connectivity distances, thus covering the continuum from the sensory input to the neural hubs supporting higher order cognitive functions. As compared to controls, adults with ADHD presented increased SFC degree within primary sensory regions and decreased SFC degree between sensory seeds and higher order integration nodes. In addition, they exhibited decreased connectivity degree between sensory seeds and regions of the default-mode network. Consistently, the higher the score in clinical severity scales the lower connectivity degree between seed regions and the default mode network.

Fronto-Limbic Connectivity as a Predictor of Improvement in Nonsuicidal Self-Injury in Adolescents Following Psychotherapy.

Objectives: Key neurobiological factors contribute to vulnerability to nonsuicidal self-injury (NSSI) among adolescents and how they respond to treatment targeted to reduce such behaviors. This study aims to examine differences in intrinsic functional connectivity between adolescents with NSSI and healthy controls (HCs) and to identify baseline connectivity markers that predict improvements in NSSI after psychotherapy. Methods: Adolescents aged 12-17 (n = 24) with repetitive NSSI along with demographically similar HCs (n = 16) underwent resting-state functional MRI scanning after which patients received up to 4 months of psychological treatment. A seed-based approach was used to examine baseline between-group differences in intrinsic functional connectivity of the amygdala and the medial prefrontal cortex (mPFC). Further analyses examined the associations between intrinsic functional connectivity at baseline and improvement in NSSI after psychological treatment. Results: Compared with HCs, adolescents with NSSI showed significantly reduced connectivity between the amygdala and the anterior cingulate cortex, subcallosal cortex, and paracingulate gyrus, as well as between the amygdala and a cluster encompassing the right planum temporale and right insula. Adolescents with NSSI, compared with HCs, also showed reduced connectivity between the mPFC and two clusters: one located in the precentral and postcentral gyri and another in the left insula. After treatment, 50% of patients reported fewer NSSI episodes compared to baseline, which was considered as improvement. Stronger negative amygdala-prefrontal connectivity was associated with greater posttreatment improvement in NSSI. Conclusions: Adolescents with NSSI may have aberrant amygdala and mPFC connectivity compared with HCs. Furthermore, stronger baseline negative amygdala-prefrontal connectivity may predict greater improvement in NSSI after psychological intervention. Given that no prior study has used resting-state functional connectivity to predict response to psychological treatment in adolescents with NSSI, replication of these findings is needed.

Pregnancy and adolescence entail similar neuroanatomical adaptations: A comparative analysis of cerebral morphometric changes.

Mapping the impact of pregnancy on the human brain is essential for understanding the neurobiology of maternal caregiving. Recently, we found that pregnancy leads to a long-lasting reduction in cerebral gray matter volume. However, the morphometric features behind the volumetric reductions remain unexplored. Furthermore, the similarity between these reductions and those occurring during adolescence, another hormonally similar transitional period of life, still needs to be investigated. Here, we used surface-based methods to analyze the longitudinal magnetic resonance imaging data of a group of 25 first-time mothers (before and after pregnancy) and compare them to those of a group of 25 female adolescents (during 2 years of pubertal development). For both first-time mothers and adolescent girls, a monthly rate of volumetric reductions of 0.09 mm3 was observed. In both cases, these reductions were accompanied by decreases in cortical thickness, surface area, local gyrification index, sulcal depth, and sulcal length, as well as increases in sulcal width. In fact, the changes associated with pregnancy did not differ from those that characterize the transition during adolescence in any of these measures. Our findings are consistent with the notion that the brain morphometric changes associated with pregnancy and adolescence reflect similar hormonally primed biological processes.

Just-in-time response to reward as a function of ADHD symptom severity.

AIM: Attention-deficit hyperactivity disorder (ADHD) neuroimaging studies have identified substantial differences in reward-related circuits on a trial-by-trial basis. However, no research to date has evaluated the effect of motivational context on neural activity in settings with intermittent reward in ADHD. The present study was designed to identify neural processes underlying both immediate effects of reward and sustained effects of reward associated with motivational context in adult ADHD patients. METHODS: We used a functional magnetic resonance imaging paradigm, including a time estimation task with constant versus intermittent reward conditions, in a sample of 21 medication-naïve adults with combined ADHD and 24 healthy adults. RESULTS: Although no between-group neural differences were detected, orbitofrontal activity dropped in association with high ADHD symptom severity during the transition from initial non-reward context blocks to subsequent reward context blocks. In turn, ADHD symptom severity predicted higher orbitofrontal activity in response to immediate reward versus no reward within reward context blocks. CONCLUSION: These results suggest that high ADHD symptom severity scorers adopted a 'just-in-time' strategy, involving the recruitment of reward processing brain areas in the face of immediate reward rather than a sustained response to motivational context.

Time and psychostimulants: Opposing long-term structural effects in the adult ADHD brain. A longitudinal MR study.

Long-term effects of psychostimulants such as methylphenidate on ADHD patients have been proved to be difficult to capture in cross-sectional studies comparing medicated and non-medicated samples and in longitudinal studies with children, with age-related maturational processes possibly confounding independent effects of medication. However, chronic psychostimulant administration at therapeutic doses has been proven to yield profound neuroadaptive changes in rodent models. Here, we present for the first time the effect of psychostimulant treatment on brain volumes in a sample of medication-naïve adult ADHD patients. We investigated grey matter volume changes in a sample of 41 medication-naïve adult ADHD patients before and after three years of psychostimulant treatment (N = 25) or no treatment (N = 16) compared to healthy adults (N = 25). We found a significant group x time interaction effect on left putamen grey matter volumes, with a decrease in left putamen volumes in the non-medicated group compared to both the medicated group and controls, and no differences between the medicated group and controls. Our results suggest a normalizing effect of psychostimulant treatment on the left putamen volume loss detected in non-medicated ADHD patients.

Pregnancy leads to long-lasting changes in human brain structure.

Pregnancy involves radical hormone surges and biological adaptations. However, the effects of pregnancy on the human brain are virtually unknown. Here we show, using a prospective ('pre'-'post' pregnancy) study involving first-time mothers and fathers and nulliparous control groups, that pregnancy renders substantial changes in brain structure, primarily reductions in gray matter (GM) volume in regions subserving social cognition. The changes were selective for the mothers and highly consistent, correctly classifying all women as having undergone pregnancy or not in-between sessions. Interestingly, the volume reductions showed a substantial overlap with brain regions responding to the women's babies postpartum. Furthermore, the GM volume changes of pregnancy predicted measures of postpartum maternal attachment, suggestive of an adaptive process serving the transition into motherhood. Another follow-up session showed that the GM reductions endured for at least 2 years post-pregnancy. Our data provide the first evidence that pregnancy confers long-lasting changes in a woman's brain.

Association between neurological soft signs, temperament and character in patients with schizophrenia and non-psychotic relatives.

The heritability of schizophrenia and most personality traits has been well established, but the role of personality in susceptibility to schizophrenia remains uncertain. The aim of this study was to test for an association between personality traits and Neurological Soft Signs (NSS), a well-known biological marker of schizophrenia, in non-psychotic relatives of patients with schizophrenia. For this purpose, we evaluated the NSS scale and personality measured by the Temperament and Character inventory (TCI-R) in three groups of subjects: 29 patients with schizophrenia, 24 unaffected relatives and 37 controls. The results showed that patients with schizophrenia were more asocial (higher harm avoidance and lower reward dependence), more perseverative (higher persistence), and more schizotypal (lower self-directedness and cooperativeness, higher self-transcendence). The unaffected relatives showed higher harm avoidance, lower self-directedness and cooperativeness than the healthy controls. Higher NSS scores and sub-scores were found in patients and non-psychotic relatives compared with the controls. Among all the patients, total NSS scores were positively correlated with harm avoidance but negatively correlated with novelty seeking and persistence. Total NSS were also correlated with low scores on self-directedness and cooperativeness, which are indicators of personality disorder. Our results show that susceptibility to NSS and to schizophrenia are both related to individual differences in the temperament and character features in non-psychotic relatives of patients with schizophrenia. High harm avoidance, low persistence, low self-directedness and low cooperativeness contribute to both the risk of NSS and schizophrenia. These findings highlight the value of using both assessments to study high risk populations.

The neuroanatomical basis of panic disorder and social phobia in schizophrenia: a voxel based morphometric study.

OBJECTIVE: It is known that there is a high prevalence of certain anxiety disorders among schizophrenic patients, especially panic disorder and social phobia. However, the neural underpinnings of the comorbidity of such anxiety disorders and schizophrenia remain unclear. Our study aims to determine the neuroanatomical basis of the co-occurrence of schizophrenia with panic disorder and social phobia. METHODS: Voxel-based morphometry was used in order to examine brain structure and to measure between-group differences, comparing magnetic resonance images of 20 anxious patients, 20 schizophrenic patients, 20 schizophrenic patients with comorbid anxiety, and 20 healthy control subjects. RESULTS: Compared to the schizophrenic patients, we observed smaller grey-matter volume (GMV) decreases in the dorsolateral prefrontal cortex and precentral gyrus in the schizophrenic-anxiety group. Additionally, the schizophrenic group showed significantly reduced GMV in the dorsolateral prefrontal cortex, precentral gyrus, orbitofrontal cortex, temporal gyrus and angular/inferior parietal gyrus when compared to the control group. CONCLUSIONS: Our findings suggest that the comorbidity of schizophrenia with panic disorder and social phobia might be characterized by specific neuroanatomical and clinical alterations that may be related to maladaptive emotion regulation related to anxiety. Even thought our findings need to be replicated, our study suggests that the identification of neural abnormalities involved in anxiety, schizophrenia and schizophrenia-anxiety may lead to an improved diagnosis and management of these conditions.

Stimulant drugs trigger transient volumetric changes in the human ventral striatum.

The ventral striatum (VStr) integrates mesolimbic dopaminergic and corticolimbic glutamatergic afferents and forms an essential component of the neural circuitry regulating impulsive behaviour. This structure represents a primary target of psychostimulant medication, the first-choice treatment for attention-deficit/hyperactivity disorder (ADHD), and is biochemically modified by these drugs in animals. However, the effects of stimulants on the human VStr remain to be determined. We acquired anatomical brain MRI scans from 23 never-medicated adult patients with ADHD, 31 adult patients with a history of stimulant treatment and 32 control subjects, and VStr volumes were determined using individual rater-blinded region of interest delineation on high-resolution neuroanatomical scans. Furthermore, we also extracted VStr volumes before and after methylphenidate treatment in a subsample of the medication-naïve adult patients as well as in 20 never-medicated children with ADHD. We observed smaller VStr volumes in adult patients with a history of stimulant treatment in comparison to never-medicated patients. Moreover, our longitudinal analyses uncovered a reduction of grey matter volume in the bilateral VStr in adult patients after exposure to methylphenidate, which was followed by volumetric recovery to control level. In children, the same pattern of VStr volume changes was observed after treatment with methylphenidate. These findings suggest that the altered VStr volumes previously observed in patients with ADHD may represent a transitory effect of stimulant exposure rather than an intrinsic feature of the disorder. More generally, these data show that stimulant drugs can render plastic volume changes in human VStr neuroanatomy.

[The neuroanatomy of attention deficit hyperactivity disorder in adults: structural and functional neuroimaging findings]. / Neuroanatomia del trastorno por deficit de atencion/hiperactividad en el adulto: hallazgos de neuroimagen estructural y funcional.

The objective of this work is to review the existing literature on findings from structural and functional magnetic resonance and connectivity. For a long time it was thought that children 'grew out' of attention deficit hyperactivity disorder (ADHD) on reaching adolescence. Yet, it is now known that up to 70% of children who present ADHD in childhood go on to present symptoms in the behavioural and cognitive sphere in adulthood. Neuroimaging studies conducted in adults with ADHD have shown alterations in the brain at the structural and functional levels, and also in terms of connectivity. These findings have been observed mainly in the inferior frontal and dorsolateral prefrontal cortex, as well as in striatal, anterior cingulate, parietotemporal and cerebellar regions. However, certain inconsistencies have also been found, which may be related with the presence of comorbidity, a history of medication, gender-related differences and the small size of the sample used in some studies. Differences have also been noted in relation to studies carried out in children with ADHD. Hence the importance for future studies of avoiding the existence of variables that can affect the findings in ADHD in adults and, moreover, of being able to determine whether the anatomical and functional deficits continue into adulthood.

Laminar thickness alterations in the fronto-parietal cortical mantle of patients with attention-deficit/hyperactivity disorder.

Although Attention-Deficit/Hyperactivity Disorder (ADHD) was initially regarded as a disorder exclusive to childhood, nowadays its prevalence in adulthood is well established. The development of novel techniques for quantifying the thickness of the cerebral mantle allows the further exploration of the neuroanatomical profiles underlying the child and adult form of the disorder. To examine the cortical mantle in children and adults with ADHD, we applied a vertex-wise analysis of cortical thickness to anatomical brain MRI scans acquired from children with (n = 43) and without ADHD (n = 41), as well as a group of adult neurotypical individuals (n = 31), adult patients with a history of stimulant treatment (n = 31) and medication-naïve adults with ADHD (n = 24). We observed several clusters of reduced laminar cortical thickness in ADHD patients in comparison to neurotypical individuals. These differences were primarily located in the dorsal attention network, including the bilateral inferior and superior parietal cortex and a section of the frontal cortex (centered on the superior frontal and precentral gyrus bilaterally). Further laminar thickness deficits were observed in the bilateral orbitofrontal cortex and medial occipital cortex. The deficits in the cortical surface were especially pronounced in the child sample, while adult patients showed a more typical laminar thickness across the cerebral mantle. These findings show that the neuroanatomical profile of ADHD, especially the childhood form of the disorder, involves robust alterations in the cortical mantle, which are most prominent in brain regions subserving attentional processing.

Ventro-striatal reductions underpin symptoms of hyperactivity and impulsivity in attention-deficit/hyperactivity disorder.

BACKGROUND: Models of attention-deficit/hyperactivity disorder (ADHD) classically emphasize the relevance of executive processes and, recently, reward circuits. The neural bases of reward processes have barely been explored in relation to this disorder, in contrast to extensive neuroimaging studies that examine executive functions in patients with ADHD. To our knowledge, no previous studies have analyzed the volume of the ventral striatum, a key region for reward processes in ADHD children. METHODS: We used a manual region-of-interest approach to examine whether there were volumetric differences in the ventral striatum of ADHD children. Forty-two children/adolescents with ADHD (ages 6-18), and 42 healthy control subjects matched on age, gender, and handedness were selected for the study. RESULTS: The ADHD children presented significant reductions in both right and left ventro-striatal volumes (t = 3.290, p = .001; and t = 3.486, p = .001, respectively). In addition, we found that the volume of the right ventral striatum negatively correlated with maternal ratings of hyperactivity/impulsivity (r = -.503, p = .003). CONCLUSIONS: Our study provides neuroanatomical evidence of alterations in the ventral striatum of ADHD children. These findings coincide with previous explicative models as well as with recent reports in behavioral and functional neuroimaging studies. Furthermore, the negative correlations we observed strongly uphold the relation between the ventral striatum and symptoms of hyperactivity/impulsivity.