Faculty Bibliography

BACKGROUND: Task-based functional magnetic resonance imaging (fMRI) studies of adult attention-deficit/hyperactivity disorder (ADHD) have revealed various ADHD-related dysfunctional brain regions, with heterogeneous findings across studies. Here, we used novel meta-analytic data-driven approaches to characterize the function and connectivity profile of ADHD-related dysfunctional regions consistently detected across studies. METHODS: We first conducted an activation likelihood estimation meta-analysis of 24 task-based fMRI studies in adults with ADHD. Each ADHD-related dysfunctional region resulting from the activation likelihood estimation meta-analysis was then analyzed using functional decoding based on ~7500 fMRI experiments in the BrainMap database. This approach allows mapping brain regions to functions not necessarily tested in individual studies, thus suggesting possible novel functions for those regions. Additionally, ADHD-related dysfunctional regions were clustered based on their functional coactivation profiles across all the experiments stored in BrainMap (meta-analytic connectivity modeling). RESULTS: ADHD-related hypoactivation was found in the left putamen, left inferior frontal gyrus (pars opercularis), left temporal pole, and right caudate. Functional decoding mapped the left putamen to cognitive aspects of music perception/reproduction and the left temporal lobe to language semantics; both these regions clustered together on the basis of their meta-analytic functional connectivity. Left inferior gyrus mapped to executive function tasks; right caudate mapped to both executive function tasks and music-related processes. CONCLUSIONS: Our study provides meta-analytic support to the hypothesis that, in addition to well-known deficits in typical executive functions, impairment in processes related to music perception/reproduction and language semantics may be involved in the pathophysiology of adult ADHD.

Understanding how the structure of cognition arises from the topographical organization of the cortex is a primary goal in neuroscience. Previous work has described local functional gradients extending from perceptual and motor regions to cortical areas representing more abstract functions, but an overarching framework for the association between structure and function is still lacking. Here, we show that the principal gradient revealed by the decomposition of connectivity data in humans and the macaque monkey is anchored by, at one end, regions serving primary sensory/motor functions and at the other end, transmodal regions that, in humans, are known as the default-mode network (DMN). These DMN regions exhibit the greatest geodesic distance along the cortical surface-and are precisely equidistant-from primary sensory/motor morphological landmarks. The principal gradient also provides an organizing spatial framework for multiple large-scale networks and characterizes a spectrum from unimodal to heteromodal activity in a functional metaanalysis. Together, these observations provide a characterization of the topographical organization of cortex and indicate that the role of the DMN in cognition might arise from its position at one extreme of a hierarchy, allowing it to process transmodal information that is unrelated to immediate sensory input.

Delayed sleep and meal times promote metabolic dysregulation and obesity. Altered coordination of sleeping and eating times may impact food reward valuation and interoception in the brain, yet the independent and collective contributions of sleep and meal times are unknown. This randomized, inpatient crossover study experimentally manipulates sleep and meal times while preserving sleep duration (7.05+/-0.44 h for 5 nights). Resting-state functional MRI scans (2 x 5-minute runs) were obtained for 4 participants (3 males; 25.3+/-4.6 y), each completing all study phases (normal sleep/normal meal; late sleep/normal meal; normal sleep/late meal; late sleep/late meal). Normal mealtimes were 1, 5, 11, and 12.5 h after awakening; late mealtimes were 4.5, 8.5, 14.5 and 16 h after awakening. Seed-based resting-state functional connectivity (RSFC) was computed for a priori regions-of-interest (seeds) and contrasted across conditions. Statistically significant (P<0.05, whole-brain corrected) regionally-specific effects were found for multiple seeds. The strongest effects were linked to the amygdala: increased RSFC for late versus normal mealtimes (equivalent to skipping breakfast). A main effect of sleep and interaction with mealtime were also observed. Preliminary findings support the feasibility of examining the effects of sleep and meal time misalignment, independent of sleep duration, on RSFC in regions relevant to food reward and interoception.International Journal of Obesity accepted article preview online, 01 August 2016. doi:10.1038/ijo.2016.132.

OBJECTIVE: To examine whether childhood attention-deficit/hyperactivity disorder (ADHD) predicts homelessness in adulthood, and whether the persistence of childhood ADHD through adolescence influences the likelihood of homelessness. METHOD: A 33-year prospective, controlled, follow-up was performed of clinic-referred, 6- to 12-year-old boys of white ethnicity with ADHD (probands; mean = 8), at a mean age of 41 years (follow-up [FU] = 41). Comparisons, children without ADHD from the same medical center, were matched for age and socioeconomic status (SES). Both groups were evaluated at a mean age of 18 years (FU18). Homelessness was assessed at FU41 in 134 of 207 probands (65%) and 136 of 178 (76%) comparisons. We tested the following: the relationship between childhood ADHD and homelessness; whether adolescent dysfunctions (conduct disorder, non-alcohol substance use disorder, arrests, and school dropout) accounted for this relationship, if found; and whether ADHD that persisted through FU18 elevated probands' homelessness rate. RESULTS: Probands had significantly higher rates of homelessness than comparisons (23.7% vs. 4.4%; chi21 = 21.15, df = 1, p < .001). In a multivariate analysis, including childhood ADHD and covariates, the probands' significant elevation of homelessness remained (odds ratio [OR] = 3.60, 95% CI = 1.32-9.76, p = .01). Probands with persistent ADHD through adolescence had significantly more homelessness than remitted probands (chi21 = 12.73, p < .001), but this relationship was no longer significant when conduct disorder at FU18 was controlled (OR = 1.97, 95% CI = 0.89-4.38, p = .09). CONCLUSION: Among boys of white ethnicity who were followed into adulthood, childhood ADHD was associated with an elevated rate of homelessness. Findings point to the need for clinical monitoring of childhood ADHD through adolescence, even when ADHD does not persist, in hopes of mitigating a cascade of malfunction that includes homelessness.

BACKGROUND: Methylphenidate and atomoxetine are commonly prescribed for treating attention deficit hyperactivity disorder (ADHD). However, their therapeutic neural mechanisms remain unclear. METHOD: After baseline evaluation including cognitive testing of the Cambridge Neuropsychological Test Automated Battery (CANTAB), drug-naive children with ADHD (n = 46), aged 7-17 years, were randomly assigned to a 12-week treatment with methylphenidate (n = 22) or atomoxetine (n = 24). Intrinsic brain activity, including the fractional amplitude of low-frequency fluctuations (fALFF) and regional homogeneity (ReHo), was quantified via resting-state functional magnetic resonance imaging at baseline and week 12. RESULTS: Reductions in inattentive symptoms were related to increased fALFF in the left superior temporal gyrus and left inferior parietal lobule for ADHD children treated with methylphenidate, and in the left lingual gyrus and left inferior occipital gyrus for ADHD children treated with atomoxetine. Hyperactivity/impulsivity symptom reductions were differentially related to increased fALFF in the methylphenidate group and to decreased fALFF in the atomoxetine group in bilateral precentral and postcentral gyri. Prediction analyses in the atomoxetine group revealed negative correlations between pre-treatment CANTAB simple reaction time and fALFF change in the left lingual gyrus and left inferior occipital gyrus, and positive correlations between pre-treatment CANTAB simple movement time and fALFF change in bilateral precentral and postcentral gyri and left precuneus, with a negative correlation between movement time and the fALFF change in the left lingual gyrus and the inferior occipital gyrus. CONCLUSIONS: Our findings suggest differential neurophysiological mechanisms for the treatment effects of methylphenidate and atomoxetine in children with ADHD.

Attention-deficit/hyperactivity disorder (ADHD) is a heritable, chronic, neurodevelopmental disorder with serious long-term repercussions. Despite being one of the most common cognitive disorders, the clinical diagnosis of ADHD is based on subjective assessments of perceived behaviors. Endophenotypes (neurobiological markers that cosegregate and are associated with an illness) are thought to provide a more powerful and objective framework for revealing the underlying neurobiology than syndromic psychiatric classification. Here, we present the results of applying genetic linkage and association analyses to neuropsychological endophenotypes using microsatellite and single nucleotide polymorphisms. We found several new genetic regions linked and/or associated with these endophenotypes, and others previously associated to ADHD, for example, loci harbored in the LPHN3, FGF1, POLR2A, CHRNA4 and ANKFY1 genes. These findings, when compared with those linked and/or associated to ADHD, suggest that these endophenotypes lie on shared pathways. The genetic information provided by this study offers a novel and complementary method of assessing the genetic causes underpinning the susceptibility to behavioral conditions and may offer new insights on the neurobiology of the disorder.Molecular Psychiatry advance online publication, 24 November 2015; doi:10.1038/mp.2015.172.

Objectives: The goals of this study are to describe long-term clinical and functional outcomes in the New York Study of hyperactive children who were followed prospectively for 33 years and identify possible predictors that influence these outcomes. Methods: White hyperactive boys (N = 207 probands) were recruited in childhood and followed in adolescence (mean age 18 years), early adulthood (mean age 25 years), and mid-adulthood (mean age 41 years). In late adolescence, 178 comparison participants were recruited. At the final followup in mid-adulthood, a total of 135 probands and 136 comparison participants (65.2 and 76.4 percent of original cohort, respectively) were assessed. Outcome measures included occupational, economic, and educational attainment and marital history, occupational and social functioning, ongoing and lifetime psychiatric disorders, hospitalizations, obesity, risk-taking behaviors, and criminal behaviors. Results: Compared with peers without ADHD, probands showed greater persistence of ADHD, along with greater prevalence of CD/antisocial personality disorder (APD) and SUD in late adolescence. These dysfunctions continued into early adulthood, even when ADHD remitted for the majority of the sample group, and were associated with deficits in educational and occupational attainment, leading to a relative economic disadvantage. Furthermore, the disproportionally high rate of CD/APD and SUD in probands versus comparison participants translated to significantly higher rates of criminality, risk-taking behavior, and risk-related medical outcomes in adulthood. Probands also showed elevated obesity rates in relation to comparison participants but no differences in mood or anxiety disorders. Conclusions: There is heterogeneity in the clinical and functional outcomes of children with ADHD. This study's findings show that childhood ADHD does not preclude adequate functioning in various life domains. However, it does predispose to maladjustment in adolescence and adulthood in a subset of these children, particularly those who develop CD/APD, an important predictor of long-term outcome

Objectives: Organizational Skills Training (OST), is a 10-week psychosocial intervention found effective in improving organizational, time management, and planning (OTMP) skills in children with Attention-Deficit/Hyperactivity Disorder (ADHD). Little is known about the feasibility of identifying brain markers for treatment response. Using resting state fMRI (R-fMRI), we aimed to examine neuronal correlates of post-treatment change as a first step toward larger controlled studies of objective predictors of treatment response. Methods: We examined pre- and post-OST R-fMRI data of 15 children (12 males; mean age: 9+/-1 year) with ADHD and significant impairments in OTMP skills indexed by total scores on Children's Organizational Skills Scales-Parent (COSS-P) or Teacher (COSS-T). Our primary outcome measure was the change in COSS-P scores. As secondary summary outcome measure, we used prepost Z-score differences averaged across COSS-T, Homework Problems Checklist, Academic Progress Report and Academic Performance Rating scales. We selected a priori the intrinsic functional connectivity (iFC) of the dorsal anterior cingulate cortex (dACC), based on its role on cognitive control. Multivariate distance matrix regression (MDMR) analysis additionally allowed for whole-brain explorations. Follow-up iFC analyses were conducted on regions with significant within-subject post-OST differences by MDMR analysis. Results: COSS-P decreased significantly (t=7.1, p< 0.0001). In a cluster involving striatum bilaterally, dACC iFC decreased post-OST; these decreases were positively correlated with COSS-P improvements (r=.34, NS) and to improvements in the summary outcome (r=.63; p<0.03). MDMR analyses revealed iFC changes in the right medial and lateral precentral cortex. Followup seed-based iFC analyses of this region showed significant decreases in cortico-striatal iFC post-OST. Conclusions: Results support the feasibility of identifying changes in brain iFC after OST. Two distinct analysis converged on decreased corticosubcortical iFC post-treatment which related to change in clinical measures. As decreases in striato-cortical iFC characterize typical development, results suggest regionally-specific enhanced maturational effects of OST

Response inhibition deficits are widely believed to be at the core of Attention-Deficit Hyperactivity Disorder (ADHD). Several studies have examined neural architectural correlates of ADHD, but research directly examining structural correlates of response inhibition is lacking. Here we examine the relationship between response inhibition as measured by a Go/No Go task, and cortical surface area and thickness of the caudal inferior frontal gyrus (cIFG), a region implicated in functional imaging studies of response inhibition, in a sample of 114 young adults with and without ADHD diagnosed initially during childhood. We used multiple linear regression models to test the hypothesis that Go/No Go performance would be associated with cIFG surface area or thickness. Results showed that poorer Go/No Go performance was associated with thicker cIFG cortex, and this effect was not mediated by ADHD status or history of substance use. However, independent of Go/No Go performance, persistence of ADHD symptoms and more frequent cannabis use were associated with thinner cIFG. Go/No Go performance was not associated with cortical surface area. The association between poor inhibitory functioning and thicker cIFG suggests that maturation of this region may differ in low performing participants. An independent association of persistent ADHD symptoms and frequent cannabis use with thinner cIFG cortex suggests that distinct neural mechanisms within this region may play a role in inhibitory function, broader ADHD symptomatology, and cannabis use. These results contribute to Research Domain Criteria (RDoC) by revealing novel associations between neural architectural phenotypes and basic neurobehavioral processes measured dimensionally.

OBJECTIVE: The purposes of this study were to examine the impact of 3 weeks of amphetamine administration on intrinsic connectome-wide connectivity patterns in adults with attention-deficit/hyperactivity disorder (ADHD) and explore the association between stimulant-induced symptom improvement and functional connectivity alteration. METHODS: Participants included 19 adults (age 20-55 years) diagnosed with ADHD using the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) criteria (American Psychiatric Association 2000 ) per the Adult Clinician Diagnostic Scale taking part in amphetamine trials. For each patient, two 6-minute resting-state functional magnetic resonance imaging (R-fMRI) scans were acquired at baseline and after treatment. A fully data-driven multivariate analytic approach (i.e., multivariate distance matrix regression [MDMR]) was applied to R-fMRI data to characterize the distributed pharmacological effects in the entire functional connectome. Clinical efficacy was assessed using ADHD rating scale with adult prompts and the Adult Self-Report Scale v1.1 Symptom Checklist. We linked stimulant-induced functional connectivity changes to symptom amelioration using Spearman's correlation. RESULTS: Three weeks of administration of a stimulant significantly reduced ADHD symptoms. MDMR-based analyses on R-fMRI data highlighted the left dorsolateral prefrontal cortex (DLPFC, a key cognitive control region) and the medial prefrontal cortex (MPFC, the anterior core of default network) whose distributed patterns of functional connectivity across the entire brain were altered by psychostimulants. Follow-up intrinsic functional connectivity revealed that stimulants specifically decreased the positive functional connectivity between DLPFC-insula, DLPFC-anterior cingulate cortex, and MPFC-insula. Importantly, these functional connectivity changes are associated with symptom improvement. CONCLUSION: These results suggested that ADHD is associated with increased functional integration or decreased functional segregation between core regions of cognitive control, default, and salience networks. The apparent normalization of intrinsic functional interaction in these circuits (i.e., increased functional segregation) may underlie the clinical benefits produced by 3 weeks of amphetamine treatment.