A dimensional-spectrum model of psychopathology: progress and opportunities.

I N THIS ISSUE OF THE ARCHIVES, KESSLER ET AL 1 provide a thorough account of the meaningof comorbidityamongDSM-IVmentaldisorders.Their contribution involved comparing hypotheses regarding the developmental sequencing of comorbidity. One hypothesis was that specific disorders are involved in specific developmental comorbidity patterns. For example, obsessive-compulsive disorder might generally be a primary disorder, with that disorder then leading people to have few social contacts owing to the debilitating nature of their symptoms. Diminished social involvementmight typicallycontribute to thedevelopment of a secondary major depressive episode in persons who have a primary diagnosis of obsessive-compulsive disorder. Numerous plausible pathways of this sort can be hypothesized.