g., nutritionists and exercise physiologists) questionnaires to recreational marathon runners.Objective With the addition of the "with limited prosocial emotions" specifier within the diagnosis of conduct disorder (DSM-5) and of conduct-dissocial disorder (ICD-11) to designate those with elevated callous-unemotional traits, the authors examined the role that callous-unemotional traits play in the risk for gun carrying and gun use during a crime in a sample at high risk for gun violence. Methods Male juvenile offenders (N=1,215) from three regions of the United States were assessed after their first arrest and then reassessed every 6 months for 36 months and again at 48 months. Callous-unemotional traits and peer gun carrying and ownership were measured via self-report after the first arrest (i.e., baseline). Gun carrying and use of a gun during a crime were self-reported at all follow-up points. Results Callous-unemotional traits at baseline increased the frequency of gun carrying and the likelihood of using a gun during a crime across the subsequent 4 years after accounting for other risk factors. Furthermore, callous-unemotional traits moderated the relationship between peer gun carrying and ownership and participant gun carrying, such that only participants low on callous-unemotional traits demonstrated increased gun carrying as a function of their peers' gun carrying and ownership. Conclusions This study demonstrates the importance of considering callous-unemotional traits in gun violence research both because callous-unemotional traits increase gun carrying and use in adolescents and because the traits may moderate other key risk factors. Notably, the influence of peer gun carrying and ownership may have been underestimated in past research for the majority of adolescents by not considering the moderating influence of callous-unemotional traits.Objective Pediatric obsessive-compulsive disorder (OCD) sometimes appears rapidly, even overnight, often after an infection. Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS, describes such a situation after infection with Streptococcus pyogenes. PANDAS may result from induced autoimmunity against brain antigens, although this remains unproven. Pilot work suggests that IgG antibodies from children with PANDAS bind to cholinergic interneurons (CINs) in the striatum. CIN deficiency has been independently associated with tics in humans and with repetitive behavioral pathology in mice, making it a plausible locus of pathology. The authors sought to replicate and extend earlier work and to investigate the cellular effects of PANDAS antibodies on cholinergic interneurons. Methods Binding of IgG to specific neurons in human and mouse brain slices was evaluated ex vivo after incubation with serum from 27 children with rigorously characterized PANDAS, both at baseline in other conditions.Objective Attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) are common neurodevelopmental disorders that frequently co-occur. The authors sought to directly compare these disorders using structural brain imaging data from ENIGMA consortium data. Methods Structural T1-weighted whole-brain MRI data from healthy control subjects (N=5,827) and from patients with ADHD (N=2,271), ASD (N=1,777), and OCD (N=2,323) from 151 cohorts worldwide were analyzed using standardized processing protocols. The authors examined subcortical volume, cortical thickness, and cortical surface area differences within a mega-analytical framework, pooling measures extracted from each cohort. Analyses were performed separately for children, adolescents, and adults, using linear mixed-effects models adjusting for age, sex, and site (and intracranial volume for subcortical and surface area measures).  https://www.selleckchem.com/products/resatorvid.html  Results No shared differences were found among all three disorders, and shared differences between any two disorders did not survive correction for multiple comparisons. Children with ADHD compared with those with OCD had smaller hippocampal volumes, possibly influenced by IQ. Children and adolescents with ADHD also had smaller intracranial volume than control subjects and those with OCD or ASD. Adults with ASD showed thicker frontal cortices compared with adult control subjects and other clinical groups. No OCD-specific differences were observed across different age groups and surface area differences among all disorders in childhood and adulthood. Conclusions The study findings suggest robust but subtle differences across different age groups among ADHD, ASD, and OCD. ADHD-specific intracranial volume and hippocampal differences in children and adolescents, and ASD-specific cortical thickness differences in the frontal cortex in adults, support previous work emphasizing structural brain differences in these disorders.Objective Psychiatric disorders commonly comprise comorbid symptoms, such as autism spectrum disorder (ASD), obsessive-compulsive disorder (OCD), and attention deficit hyperactivity disorder (ADHD), raising controversies over accurate diagnosis and overlap of their neural underpinnings. The authors used noninvasive neuroimaging in humans and nonhuman primates to identify neural markers associated with DSM-5 diagnoses and quantitative measures of symptom severity. Methods Resting-state functional connectivity data obtained from both wild-type and methyl-CpG binding protein 2 (MECP2) transgenic monkeys were used to construct monkey-derived classifiers for diagnostic classification in four human data sets (ASD Autism Brain Imaging Data Exchange [ABIDE-I], N=1,112; ABIDE-II, N=1,114; ADHD-200 sample N=776; OCD local institutional database N=186). Stepwise linear regression models were applied to examine associations between functional connections of monkey-derived classifiers and dimensional symptom severity of psychiatric disorders. Results Nine core regions prominently distributed in frontal and temporal cortices were identified in monkeys and used as seeds to construct the monkey-derived classifier that informed diagnostic classification in human autism. This same set of core regions was useful for diagnostic classification in the OCD cohort but not the ADHD cohort. Models based on functional connections of the right ventrolateral prefrontal cortex with the left thalamus and right prefrontal polar cortex predicted communication scores of ASD patients and compulsivity scores of OCD patients, respectively. Conclusions The identified core regions may serve as a basis for building markers for ASD and OCD diagnoses, as well as measures of symptom severity. These findings may inform future development of machine-learning models for psychiatric disorders and may improve the accuracy and speed of clinical assessments.