Prevalence of affective disorders in children and adolescents: findings from the Zurich epidemiological studies

OBJECTIVE: Affective disorders were studied in two epidemiological studies of children and adolescents in the Canton of Zurich, Switzerland. METHOD: In the Zurich Epidemiological Study of Child and Adolescent Psychopathology Study (ZESCAP) in 1994 a representative cohort of 1964 pupils aged 7-16 years was studied. The Zurich Adolescent Psychology and Psychopathology Study (ZAPPS) included 1089 adolescents aged 15-19 years who were assessed in 1997. A two-stage approach with questionnaire screening of the entire sample in stage 1 and consecutive interviews in stage 2 was used in both studies. Diagnoses according to DSM-III-R were derived from structured parent interviews in the ZESCAP and from both parent and adolescent interviews in the ZAPPS. RESULTS: The total prevalence rate for affective disorders in the ZESCAP was 0.66% (SE 0.25) whereas it was 5.1% based on adolescent interviews and 1.2% based on parent interviews in the ZAPPS. Adolescent girls have significantly higher prevalence rates for affective disorders than boys (9.4 vs. 1.1%). CONCLUSION: These findings are in accordance with various other international epidemiological studies on affective disorders in children and adolescents.