Abstract
Previous research suggests that patterns of comorbidity of common mental disorders among adults are best reflected by a hierarchical three-factor structure with two correlated factors ('anxious-misery' and 'fear') summarized in a second-order 'internalizing' factor and one 'externalizing' factor. This three-factor structure has not been examined yet in a sample of adolescents and young adults.A representative sample of 3021 adolescents and young adults (baseline age 14-24) were prospectively followed over 10 years. Mental disorders were assessed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) by using the standardized Munich Composite International Diagnostic Interview. Ten mental disorders (major depressive episode, dysthymia, generalized anxiety disorder, social phobia, specific phobia, agoraphobia, panic disorder, alcohol dependence, drug dependence, antisocial personality) were fitted to a series of Confirmatory Factor Analysis models using: (1) 12-month data, and (2) lifetime data from a person-year data set.The three-factor model showed good fit to the observed data in our sample both when 12-month diagnoses and lifetime-to-date diagnoses from a person-year data file were used; yet the higher-order 'internalizing' factor summarizing 'anxious misery' and 'fear' had to be omitted.The three-factor model could be replicated in a sample of adolescents and young adults with the exception that the second-order 'internalizing' factor was not consistent with the data. Further research is necessary to provide more complete insight into the structure of mental disorders by examining the stability of the structure of mental disorders in different developmental stages (ages) and by using a more extensive set of mental disorders.