Faculty Bibliography

OBJECTIVE:Sleep disturbances are a feature of attention-deficit/hyperactivity disorder (ADHD) and an adverse event (AE) of methylphenidate treatment. The authors sought to clarify methylphenidate-associated sleep problems and how studies are affected by confounding factors. DATA SOURCES/METHODS:Published studies in English collected via online databases and unpublished data from www.clinicaltrials.gov and US Food and Drug Administration websites. Sources were searched from inception to August 2017. STUDY SELECTION/METHODS:Included were blinded placebo-controlled studies of youth with ADHD conducted in naturalistic settings, leading to 35 studies yielding 75 observations of sleep-related AEs. These studies comprised 3,079 drug-exposed and 2,606 placebo-treated patients. DATA EXTRACTION/METHODS:Two PhD-level reviewers reviewed each study for inclusion. Four PhD/PharmD-level reviewers extracted data in duplicate. Discrepancies were resolved by discussion or, if needed, by the senior author. RESULTS:Increased pooled relative risks (RRs) were found for methylphenidate-associated sleep-related AEs for insomnia (general), initial insomnia, middle insomnia, combined insomnia, and sleep disorder. Several sample or study design features were significantly associated with the RR for sleep-related AEs and the methylphenidate formulation studied (P < .05). After correction for confounding variables, significant differences among drugs were found for initial insomnia, insomnia (general), and sleep disorder (P < .0001) as the other categories could not be tested due to insufficient studies. The findings also show that the RR and its interpretation are constrained by the placebo AE rate. CONCLUSIONS:Several types of insomnia and sleep problems are associated with methylphenidate treatment. Study design and sample features influence the RR statistic. By showing that the rate of placebo AEs impacts the RR, this study provides the field with a useful covariate for adjusting RR statistics.

Major depressive disorder (MDD) is common and disabling, but its neuropathophysiology remains unclear. Most studies of functional brain networks in MDD have had limited statistical power and data analysis approaches have varied widely. The REST-meta-MDD Project of resting-state fMRI (R-fMRI) addresses these issues. Twenty-five research groups in China established the REST-meta-MDD Consortium by contributing R-fMRI data from 1,300 patients with MDD and 1,128 normal controls (NCs). Data were preprocessed locally with a standardized protocol before aggregated group analyses. We focused on functional connectivity (FC) within the default mode network (DMN), frequently reported to be increased in MDD. Instead, we found decreased DMN FC when we compared 848 patients with MDD to 794 NCs from 17 sites after data exclusion. We found FC reduction only in recurrent MDD, not in first-episode drug-naïve MDD. Decreased DMN FC was associated with medication usage but not with MDD duration. DMN FC was also positively related to symptom severity but only in recurrent MDD. Exploratory analyses also revealed alterations in FC of visual, sensory-motor, and dorsal attention networks in MDD. We confirmed the key role of DMN in MDD but found reduced rather than increased FC within the DMN. Future studies should test whether decreased DMN FC mediates response to treatment. All R-fMRI indices of data contributed by the REST-meta-MDD consortium are being shared publicly via the R-fMRI Maps Project.

Precise timing makes the difference between harmony and cacophony, but how the brain achieves precision during timing is unknown. In this study, human participants (7 females, 5 males) generated a time interval while being recorded with magnetoencephalography. Building on the proposal that the coupling of neural oscillations provides a temporal code for information processing in the brain, we tested whether the strength of oscillatory coupling was sensitive to self-generated temporal precision. On a per individual basis, we show the presence of alpha-beta phase-amplitude coupling whose strength was associated with the temporal precision of self-generated time intervals, not with their absolute duration. Our results provide evidence that active oscillatory coupling engages α oscillations in maintaining the precision of an endogenous temporal motor goal encoded in β power; the when of self-timed actions. We propose that oscillatory coupling indexes the variance of neuronal computations, which translates into the precision of an individual's behavioral performance.SIGNIFICANCE STATEMENT Which neural mechanisms enable precise volitional timing in the brain is unknown, yet accurate and precise timing is essential in every realm of life. In this study, we build on the hypothesis that neural oscillations, and their coupling across time scales, are essential for the coding and for the transmission of information in the brain. We show the presence of alpha-beta phase-amplitude coupling (α-β PAC) whose strength was associated with the temporal precision of self-generated time intervals, not with their absolute duration. α-β PAC indexes the temporal precision with which information is represented in an individual's brain. Our results link large-scale neuronal variability on the one hand, and individuals' timing precision, on the other.

OBJECTIVE/UNASSIGNED:Neuroimaging studies show structural alterations of various brain regions in children and adults with attention deficit hyperactivity disorder (ADHD), although nonreplications are frequent. The authors sought to identify cortical characteristics related to ADHD using large-scale studies. METHODS/UNASSIGNED:Cortical thickness and surface area (based on the Desikan-Killiany atlas) were compared between case subjects with ADHD (N=2,246) and control subjects (N=1,934) for children, adolescents, and adults separately in ENIGMA-ADHD, a consortium of 36 centers. To assess familial effects on cortical measures, case subjects, unaffected siblings, and control subjects in the NeuroIMAGE study (N=506) were compared. Associations of the attention scale from the Child Behavior Checklist with cortical measures were determined in a pediatric population sample (Generation-R, N=2,707). RESULTS/UNASSIGNED:In the ENIGMA-ADHD sample, lower surface area values were found in children with ADHD, mainly in frontal, cingulate, and temporal regions; the largest significant effect was for total surface area (Cohen's d=-0.21). Fusiform gyrus and temporal pole cortical thickness was also lower in children with ADHD. Neither surface area nor thickness differences were found in the adolescent or adult groups. Familial effects were seen for surface area in several regions. In an overlapping set of regions, surface area, but not thickness, was associated with attention problems in the Generation-R sample. CONCLUSIONS/UNASSIGNED:Subtle differences in cortical surface area are widespread in children but not adolescents and adults with ADHD, confirming involvement of the frontal cortex and highlighting regions deserving further attention. Notably, the alterations behave like endophenotypes in families and are linked to ADHD symptoms in the population, extending evidence that ADHD behaves as a continuous trait in the population. Future longitudinal studies should clarify individual lifespan trajectories that lead to nonsignificant findings in adolescent and adult groups despite the presence of an ADHD diagnosis.

OBJECTIVE:The habenula is a small region in the epithalamus that contributes to the regulation of midbrain dopaminergic circuits implicated in attention-deficit hyperactivity disorder (ADHD). This investigation aims to evaluate the intrinsic functional connectivity (iFC) of the habenula in children with ADHD. METHOD/METHODS:A total of 112 children (5-9 years; 75 ADHD, 37 healthy comparisons) completed anatomical and resting-state functional magnetic resonance imaging (MRI) scans. Habenula regions of interest (ROIs) were identified individually on normalized T1-weighted anatomical images. Seed-based iFC analyses and group comparisons were conducted for habenula ROIs, as well as thalamic ROIs to test the specificity of habenula findings. RESULTS:Children with ADHD exhibited reduced habenula-putamen iFC compared with healthy comparisons. Group differences in thalamic iFC showed no overlap with habenular findings. CONCLUSION/CONCLUSIONS:These preliminary findings suggest that habenula-putamen iFC may be disrupted in children with ADHD. Further work is needed to confirm and elucidate the role of this circuit in ADHD pathophysiology.

OBJECTIVE:There is no standard method for assessing symptoms of the prodrome to bipolar disorder (BD), which has limited progress toward early identification and intervention. We aimed to validate the Bipolar Prodrome Symptom Scale-Abbreviated Screen for Patients (BPSS-AS-P), a brief self-report derived from the validated, clinician-rated Bipolar Prodrome Symptom Interview and Scale-Full Prospective (BPSS-FP), as a means to screen and identify people for whom further evaluation is indicated. METHOD/METHODS:Altogether, 134 participants (aged 12-18 years) were drawn from a study of the pre-syndromal stage of mood and psychotic disorders. All participants had chart diagnoses of a mood- or psychosis-spectrum disorder. Participants were interviewed with the BPSS-FP and completed measures of mania and non-mood psychopathology. Prior to being interviewed, patients completed the BPSS-AS-P. Scores on the BPSS-AS-P were determined by summing the severity and frequency ratings for each item. RESULTS:BPSS-AS-P scores were highly reliable (Cronbach's alpha = 0.94) and correlated with the interview-based BPSS-FP Mania Symptom Index (r = 0.55, p < .0001). BPSS-AS-P scores had good convergent validity, correlating with the General Behavior Inventory-10M (r = 0.65, p < .0001) and Young Mania Rating Scale; r = 0.48, p < .0001). The BPSS-AS-P had good discriminant validity, not being correlated with scales measuring positive and negative symptoms of psychotic disorders (p-values = 0.072-0.667). LIMITATIONS/CONCLUSIONS:Findings are limited by the cross-sectional nature of the study by the fact that the participants were all treatment-seeking. Future studies need to evaluate the predictive validity of the BPSS-AS-P for identifying those who develop BD in a community sample. CONCLUSION/CONCLUSIONS:BPSS-AS-P has promise as a screening tool for people at risk for BD. Adopting the BPSS-AS-P would support the goal of characterizing the prodrome systematically in order to facilitate research and clinical care.

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with social communication deficits and restricted/repetitive behaviors and is characterized by large-scale atypical subcortical-cortical connectivity, including impaired resting-state functional connectivity between thalamic and sensory regions. Previous studies have typically focused on the abnormal static connectivity in ASD and overlooked potential valuable dynamic patterns in brain connectivity. However, resting-state brain connectivity is indeed highly dynamic, and abnormalities in dynamic brain connectivity have been widely identified in psychiatric disorders. In this study, we investigated the dynamic functional network connectivity (dFNC) between 51 intrinsic connectivity networks in 170 individuals with ASD and 195 age-matched typically developing (TD) controls using independent component analysis and a sliding window approach. A hard clustering state analysis and a fuzzy meta-state analysis were conducted respectively, for the exploration of local and global aberrant dynamic connectivity patterns in ASD. We examined the group difference in dFNC between thalamic and sensory networks in each functional state and group differences in four high-dimensional dynamic measures. The results showed that compared with TD controls, individuals with ASD show an increase in transient connectivity between hypothalamus/subthalamus and some sensory networks (right postcentral gyrus, bi paracentral lobule, and lingual gyrus) in certain functional states, and diminished global meta-state dynamics of the whole-brain functional network. In addition, these atypical dynamic patterns are significantly associated with autistic symptoms indexed by the Autism Diagnostic Observation Schedule. These converging results support and extend previous observations regarding hyperconnectivity between thalamic and sensory regions and stable whole-brain functional configuration in ASD. Dynamic brain connectivity may serve as a potential biomarker of ASD and further investigation of these dynamic patterns might help to advance our understanding of behavioral differences in this complex neurodevelopmental disorder.

We report the first experimental results on spin-dependent elastic weakly interacting massive particle (WIMP) nucleon scattering from the XENON1T dark matter search experiment. The analysis uses the full ton year exposure of XENON1T to constrain the spin-dependent proton-only and neutron-only cases. No significant signal excess is observed, and a profile likelihood ratio analysis is used to set exclusion limits on the WIMP-nucleon interactions. This includes the most stringent constraint to date on the WIMP-neutron cross section, with a minimum of 6.3×10^{-42}  cm^{2} at 30  GeV/c^{2} and 90% confidence level. The results are compared with those from collider searches and used to exclude new parameter space in an isoscalar theory with an axial-vector mediator.

OBJECTIVES/OBJECTIVE:Recent magnetic resonance imaging (MRI) studies implicate structural alterations of amygdala, a brain region responsible for processing and experiencing negative emotions, in adolescents with attention-deficit/hyperactivity disorder (ADHD). Here we examined ADHD-related structural correlates of amygdala functional activity elicited during a functional MRI task designed to test behavioural and brain responses to the imposition of delay - an event known to both elicit amygdala hyperactivation and aversity in ADHD. METHODS:Structural MRI scans from 28 right-handed male adolescents with combined type ADHD and 32 age-matched controls were analysed. Regional grey matter volumes of ADHD and control participants (P[FWE] < 0.05) were correlated with delay aversion self-ratings and neural activity in response to delay-related cues on the Escape Delay Incentive fMRI task. RESULTS:ADHD was associated with significantly reduced volumes in bilateral amygdala, parahippocampal and temporal gyrus (P[FWE] < 0.05), greater basolateral amygdala activation to delay-related cues (P[FWE] < 0.05) and higher delay aversion self-ratings. Amygdala volume reductions were significantly correlated with, and statistically mediated the pathway from ADHD to, delay-cue-related amygdala hyperactivity (P < 0.01) and self-reported delay aversion (P < 0.01). CONCLUSIONS:We provide the first evidence of the functional significance of reduced amygdala volumes in adolescents with ADHD by highlighting its relation to delay-induced brain activity that is linked to delay aversion.

BACKGROUND:Disruptive Behavioral Disorders (DBDs) and Attention Deficit/Hyperactivity Disorder (ADHD) are chronic, impairing, and costly child and adolescent mental health challenges which, when untreated, can result in disruptions in school performance, friendships and family relations. Yet, there is dearth of prevalence data on child and adolescent behavioral challenges within sub-Saharan Africa, including Uganda. This study aims to estimate the prevalence rate of behavioral challenges and ADHD among young school going children and early adolescents (ages 8-13 at study enrollment), utilizing a school-based sample in southwest Uganda. METHODS:We present screening results from a 5-year scale-up study titled SMART Africa-Uganda (2016-2021), set across 30 public primary schools located in the greater Masaka region in Uganda, a region heavily impacted by poverty and HIV/AIDS. Specifically, we draw on screening data from caregivers of 2434 children that used well-established standardized measures that had been pre-tested in the region. These were: 1) oppositional defiant disorder (ODD) and conduct disorder (CD) subscales of the Disruptive Behavior Disorders (DBD) scale; and 2) the Iowa Connors and Impairment scales. Slightly over half of the children in the sample were female (52%), with a mean age of 10.27 years. RESULTS:Of the 2434 participants screened for disruptive behaviors: 1) 6% (n = 136) scored positive on ODD and 2% (n = 42) scored positive on CD subscales of the DBD scale; 2) 9.61% (n = 234), and 2.67% (n = 65) were reported to have elevated symptoms of ODD and ADHD on the Iowa Connors caregiver report scale respectively. Twenty-five percent (n = 586) of children were described by their caregivers as having experienced some form of impairment in at least four domains of the Impairment scale. CONCLUSION/CONCLUSIONS:The results indicate the presence of behavioral challenges and ADHD among school going children, aged 8-13 years, in Uganda. Given the negative outcomes associated with behavioral challenges as children transition to adolescence and adulthood, detecting these emerging behavioral challenges early is critical in developing appropriate interventions. School settings could be considered as one of the contextually-relevant, culturally-appropriate, and non-stigmatizing venues to implement screening procedures and to detect emerging behavioral challenges and to make necessary referrals.