Characteristics of child psychiatric outpatients with slow processing speed and potential mechanisms of academic impact.

While slow processing speed (PS) is well documented in youth with ADHD, growing evidence suggests that this difficulty affects children with other neuropsychiatric conditions. Clarifying the relationship between slow PS and different forms of psychopathology is important clinically, given the potential impact of PS on academic functioning, and conceptually. In 751 youth, ages 6-21, consecutively referred for neuropsychiatric evaluation, we examined the association between slow PS (i.e., Wechsler PS Index < 85) and seven neuropsychiatric diagnostic groups. In 492 of these youth, we also related slow PS to eight psychopathology symptom dimensions. Finally, we modeled the relationship between PS, other cognitive functions and academic achievement. Data are from the Longitudinal Study of Genetic Influences on Cognition. Analyses included one-sample t tests, ANOVA, logistic regression, mixed modeling, and structural equation modeling (SEM), controlling for age, sex, and medication. Compared to normative data, all clinical groups showed PS decrements. Compared to referred youth without full diagnoses and accounting for other psychopathology, risk for slow PS was elevated in youth with autism spectrum disorder (OR = 1.8), psychotic disorders (OR = 3.4) and ADHD-inattentive type (OR = 1.6). Having multiple comorbidities also increased risk for slow PS. Among dimensions, inattention (OR = 1.5) associated with slow PS but did not fully explain the association with autism or psychosis. In SEM, PS had direct effects on academic achievement and indirect effects through working memory. Findings extend evidence that PS relates to multiple aspects of child psychopathology and associates with academic achievement in child psychiatric outpatients.

Translating Discoveries in Attention-Deficit/Hyperactivity Disorder Genomics to an Outpatient Child and Adolescent Psychiatric Cohort.

OBJECTIVE: Genomic discoveries should be investigated in generalizable child psychiatric samples in order to justify and inform studies that will evaluate their use for specific clinical purposes. In youth consecutively referred for neuropsychiatric evaluation, we examined 1) the convergent and discriminant validity of attention-deficit/hyperactivity disorder (ADHD) polygenic risk scores (PRSs) in relation to DSM-based ADHD phenotypes; 2) the association of ADHD PRSs with phenotypes beyond ADHD that share its liability and have implications for outcome; and 3) the extent to which youth with high ADHD PRSs manifest a distinctive clinical profile. METHOD: Participants were 433 youth, ages 7-18 years, from the Longitudinal Study of Genetic Influences on Cognition. We used logistic/linear regression and mixed effects models to examine associations with ADHD-related polygenic variation from the largest ADHD genome-wide association study to date. We replicated key findings in 5,140 adult patients from a local health system biobank. RESULTS: Among referred youth, ADHD PRSs were associated with ADHD diagnoses, cross-diagnostic ADHD symptoms and academic impairment (odds ratios ∼1.4; R2 values ∼2%-3%), as well as cross-diagnostic variation in aggression and working memory. In adults, ADHD PRSs were associated with ADHD and phenotypes beyond the condition that have public health implications. Finally, youth with a high ADHD polygenic burden showed a more severe clinical profile than youth with a low burden (ß coefficients ∼.2). CONCLUSION: Among child and adolescent outpatients, ADHD polygenic risk was associated with ADHD and related phenotypes as well as clinical severity. These results extend the scientific foundation for studies of ADHD polygenic risk in the clinical setting and highlight directions for further research.

Characteristics of Child Psychiatric Outpatients at Highest Risk for Suicidal Thoughts and Behaviors.

On average, compared to non-referred youth, child psychiatric outpatients show elevated rates of suicidal thoughts and behaviors (STBs), which are predictors of completed suicide. Determining the psychopathology features that associate with highest risk for STBs among youth outpatients may yield opportunities for targeted prevention/intervention. Yet, outpatient studies are limited and have not systematically examined comorbidity and dimensional psychopathology. In 758 youth, aged 6-18, consecutively referred for neuropsychiatric evaluation, we examined the extent to which diagnostic groups, comorbid subgroups and dimensional symptoms associated with STBs. After controlling for comorbidity, mood, anxiety and conduct disorders associated with elevated STB risk. Regarding dimensions, symptoms of depression, aggression and psychosis all contributed to higher STB risk. Although ADHD (as a diagnosis or dimension) did not associate with elevated STB risk independently, ADHD that was comorbid with other conditions did. Suicide prevention/intervention efforts should be investigated in youth outpatients with the highest risk for STBs.