CHILDHOOD-ONSET DYSTHYMIC DISORDER - CLINICAL-FEATURES AND PROSPECTIVE NATURALISTIC OUTCOME

Objectives: To characterize the clinical presentation, course, and out come of childhood-onset dysthymic disorder and assess the predictive v alidity of this diagnosis. Design: As part of a longitudinal prospecti ve study, school-age, clinically referred youngsters (n=55) whose firs t depression was dysthymic disorder and a comparison group of youngste rs (n=60) whose first affective episode was major depressive disorder (MDD) were repeatedly examined during a 3- to 12-year interval. The di agnoses were based on DSM-III criteria. Results: Dysthymic disorder wa s associated with earlier age at onset than MDD, similarly frequent sy mptoms of affective dysregulation, but low rates of anhedonia and neur ovegetative symptoms and greater overall risk of any subsequent affect ive disorder. The affective disorders that dysthymic children develope d, including first-episode MDD (76%) and bipolar disorder ((13%), far outnumbered nonaffective conditions. After the first episode of MDD, t he clinical course of the initially dysthymic youths was similar to th e course of the comparison patients with regard to rates of recurrent major depression, bipolar disorder, and certain nonaffective disorders . Conclusions: Childhood-onset dysthymic disorder is an early marker o f recurrent affective illness. Although on long-term follow-up, dysthy mic disorder and MDD are associated with similar rates of certain outc omes, there exist sufficient differences to warrant diagnosis of each disorder. Dysthymic children who have subsequent mood disorders are mo st likely first to have an episode of MDD, and that episode appears to be the ''gateway'' to recurrent affective illness. The interval betwe en the onset of dysthymia and the first major depression provides a wi ndow of opportunity for intervention and possible prevention of later episodes.