Background: Social anxiety disorder (SAD) (also known as "social phobia") is frequently comorbid with major depression, and in such cases, almost always precedes it. This has led to interest in SAD as a possible modifier of the risk and/or course of mood disorders.
Methods: Data come from a prospective, longitudinal epidemiologic study of adolescents and young adults (aged 14-24 years) in Munich, Germany. Respondent diagnoses (N = 2548) at baseline and follow-up (34-50 months later) are considered. The influence of SAD at baseline on the risk, course, and characteristics of depressive disorders (ie, major depression or dysthymia) at follow-up is examined.
Results: The baseline prevalence of SAD was 7.2% (95% confidence interval [CI], 6.1%-8.4%). Social anxiety disorder in nondepressed persons at baseline was associated with an increased likelihood (odds ratio [OR] = 3.5; 95% CI, 2.0-6.0) of depressive disorder onset during the follow-up period. Furthermore, comorbid SAD and depressive disorder at baseline was associated with a worse prognosis (compared with depressive disorder without comorbid SAD at baseline). This is exemplified by the greater likelihood of depressive disorder persistence or recurrence (OR = 2.3; 95% CI, 1.2-4.6) and attempted suicide (OR = 6.1; 95% CI, 1.2-32.2).
Conclusions: Social anxiety disorder during adolescence or young adulthood is an important predictor of subsequent depressive disorders. Moreover, the presence of comorbid SAD in adolescents who are already depressed is associated with a more malignant course and character of subsequent depressive illness. These findings may inform targeted intervention efforts.