Although the NCS-A survey was conducted 10 years ago, no population-based adolescent studies in the U.S. could compete with its data richness yet. Data collected from the NCS-A covered diagnostic information for 16 psychiatric disorders, demographic characteristics, developmental background, and individual, family and environmental factors. The prevalence, comorbidity, and correlates of mental disorders in adolescents generated from the NCS-A survey have been widely cited and its data have been analyzed in-depth, especially since its release to the public in 2011. During the past year, we have actively worked on projects of relevance to the goals of our research branch including: (1) prevalence, correlates and service patterns for major depression in adolescents; (2) patterns of comorbidity (mental and physical comorbidity patterns in autism and pervasive developmental disorders); (3) physical disorders and attention deficit hyperactivity disorder (ADHD); (4) obesity and bipolar disorder; (5) substance use disorder and other prior mental disorders; and (6) sleep patterns and mental health problems. We have also explored the implications of newly conceptualized DSM-5 disorders (e.g. disruptive mood dysregulation disorder (DMDD) and ADHD when extended the age of onset from 7 to 12 years old). The research yielded several peer-reviewed publications. The chief findings include: -Major depressive disorder (MDD) was common in adolescence (lifetime and 12-month prevalence were 11.0% and 7.5%, respectively). The prevalence of MDD increased significantly across adolescence, with markedly greater increases among females than males. Most cases of MDD were associated with psychiatric comorbidity and severe role impairment, and a substantial minority reported suicidality. The prevalence of severe MDD was about a quarter of that of all MDD cases; estimates of impairment and clinical correlates were of 2- to 5-fold greater magnitude for severe versus mild/moderate depression, with markedly higher rates for suicidal thoughts and behaviors. Treatment in any form was received by the majority of adolescents with 12-month DSM-IV MDD (60.4%), but only a minority received treatment that was disorder-specific or from the mental health sector (Avenevoli et al, 2015). -The results of a sophisticated analysis of the association between school start time and reduced sleep time show that delaying school start time to 8 am may have an important benefit in increasing adolescent sleep duration. Our work on the adverse effects of insomnia in adolescents also demonstrated the health consequences of inadequate sleep (Blank et al, 2015). Because obtaining adequate sleep is protective against a number of adverse health conditions, interventions that help adolescents achieve optimal sleep patterns will hopefully benefit both short- and long-term health (Paksarian et al, 2015). -Using a novel approach to examine the clustering of disorders, we found that the interrelationships among 12-month psychiatric disorders were well described by three or four correlated dimensions, representing different facets of underlying internalizing and externalizing dimensions. These dimensions are hierarchically organized, allowing for clinical and research analyses at different levels of organization. Findings suggest that individuals with psychiatric disorders present with a broad of range of liabilities, reflecting the diversity of their clinical presentations. These findings have nosological, etiological and clinical implications for adolescent psychiatric disorders (Blanco et al, 2015). -While accessing the utility of the new DSM-5 label for DMDD, we concluded that the DSM-5 DMDD diagnosis captures a small group of adolescents with multiple other psychiatric and neurologic conditions. The specificity of this diagnostic label, therefore, at least in adolescents, remains an open question (Althoff et al, in press, Journal of Child and Adolescent Psychopharmarcology). Public Health Impact: As the first study of comprehensive domains of emotional and behavior disorders in a nationally representative sample of U.S. youth, the results have had significant public health impact. The striking rates of serious depression in adolescents, coupled with the relatively low proportion who receive mental health services, underscores the urgent need for greater effort to address adolescent depression in the mental health system. This is of particular concern because of the risk of suicide and other impacts on adolescent life functioning. The finding of the widespread lack of adequate sleep in adolescents, that could be partially ameliorated by a change in school start time, is also a major public health challenge to adolescent health. Future Plans: We will continue to analyze these rich data, both within our research group and the National Institute of Mental Health, as well as to provide support to investigators outside the National Institutes of Health. Several important manuscripts are now in progress that will continue to provide knowledge about adolescent mental health in the general population. We are currently focusing on the following areas: -Examine the overall prevalence of prior mental disorders among adolescents having attained each stage of substance use (from first use to dependence) and estimate the influence of prior mental disorders in the probability of transition from earlier to later stage of use: We found the burden of substance use disorders in adolescence is disproportionately concentrated among youth with prior mental disorders, and that this burden is not limited to treated samples (Conway et al, 2015). -Examine the association of overweight/obesity and bipolar disorder: In contrast to adults, overweight or obesity is not excessively prevalent among adolescents with bipolar disorder. Similar to adults, overweight or obesity among adolescents with bipolar disorder is associated with multiple indicators of risk and of bipolar severity. Prevention and treatment of overweight or obesity in adolescents with bipolar disorder may serve the dual purpose of optimizing physical and mental health (Goldstein et al, 2015). - Investigate the overall prevalence and overlap between autism spectrum disorder (ASD) and learning disability (LD) in the NCS-A: ASD is a neurodevelopmental disorder that is highly comorbid with LD. Several conditions, including allergy, are specifically associated with ASD. However, gastrointestinal problems, epilepsy/seizures, and ADHD are associated with both ASD and LD in our population-based sample, indicating an association with general neurodevelopment (Sheppard et al, 2015). -Examine physical comorbidity among adolescents with a diagnosis of ADHD: We found that among various physical conditions examined, enuresis and serious stomach or bowel problems were the strongest comorbid conditions of ADHD. These findings confirm the pervasive physical comorbidity of ADHD reported in previous clinical and community-based studies. The evidence for specific associations between ADHD with enuresis and serious stomach or bowel conditions may also provide an important clue to multisystem involvement in ADHD (Jameson et al, 2015). -Review the distribution of sleep patterns and their associations with mental disorders: We found that inadequate sleep may increase the risk of mental disorder onset. Sleep pattern variability was also associated with tobacco smoking and perceived mental and physical health. (Zhang et al, 2015). -Access the generalizability of adolescent clinical trials of major depressive disorder; given that current practice of the clinical trials likely exclude a great majority of adolescents with major depressive disorder (Blanco et al, 2015).