Emergence of gender differences in depression during adolescence: national panel results from three countries.

Objective: Although the gender gap in depression among adults is well established, the age at which this phenomenon appears during adolescence is less clear. To address this, the authors present a cross-national examination of the emergence of the gender gap in depression during adolescence using national longitudinal panel data from Canada, Great Britain, and the United States.

Method: The two-wave, 1994-1996 Canadian National Population Health Survey uses a diagnostic measure across a 24-month interval, providing 12-month prevalence rates of major depressive disorder. The British Youth Panel measures depressive symptomatology across five annual waves beginning in 1995. The two-wave, 1995-1996 National Longitudinal Study of Adolescent Health uses a measure of depressive symptomatology across a 12-month interval.

Results: Females have significantly higher rates of depression for each sample overall. When samples are decomposed by age, the gender gap in depression consistently emerges by age 14 across all three national samples, irrespective of the measure used or whether categorical cutoffs or untransformed scale scores are used to assess depressive symptomatology.

Conclusions: There is a consistent pattern in the onset of the gender gap in depression at age 14 across all three countries and measures. This consistency provides important etiologic clues concerning underlying causes of depression and identifies at what age diagnosis, treatment, and intervention strategies should be directed.