Do anxiety and depression cluster into distinct groups?: a test of tripartite model predictions in a community sample of youth.

Because of their high comorbidity and strong associations, the distinctiveness of anxiety and depression in youth continues to be debated. In this study we used cluster analysis in a community sample (n=225) of youth to test tripartite model predictions regarding the grouping of individuals based on their levels of anxiety and depression symptoms. Findings were consistent with tripartite model predictions that four groups would emerge (primarily elevated on anxiety symptoms only, elevated on depression symptoms only, elevated on both anxiety and depression symptoms, and a low symptom group). Analyses using specific tripartite model variables and parent report of internalizing symptoms provided additional support for the groupings and tripartite model predictions. Across age groupings, the clustering of anxiety and depression symptoms was consistent with some hypothesized developmental differences in the expression of internalizing symptoms in youth. Findings add support for the tripartite model in youth, and support the idea that anxiety and depression do represent unique syndromes in youth. Depression and Anxiety 23:453-460, 2006. Published 2006 Wiley-Liss, Inc.