Longitudinal Clustering of Psychopathology Across Childhood and Adolescence: An Approach Toward Developmentally Based Classification

Current classification systems of psychopathology focus on cross-sectional symptomatology rather than continuity, discontinuity and comorbidity across development. Here, a community sample of 600 youth was assessed every 3 years from early childhood through late adolescence using semi-structured diagnostic interviews. We used longitudinal <i>k</i>-means clustering of joint-diagnostic trajectories to identify 6 distinct clusters (healthy, childhood anxiety, childhood/adolescent ADHD, adolescent depression/anxiety, adolescent depression/substance use, and early childhood disruptive behavior). When comparing psychopathology clusters to the healthy cluster on age 3 predictors (parental education and psychopathology, early environment, temperament, cognitive and social functioning) and age 18 functional outcomes, the clusters captured developmental patterning of psychopathology not apparent in cross-sectional nosology. The study serves as a proof of principle in applying a longitudinal clustering approach to common mental disorders, affording a rich perspective on the unfolding of sequential comorbidity and heterotypic continuity and identifying transdiagnostic subgroups with meaningful clinical, family, and temperamental correlates.