Prevalence and correlates of bipolar I disorder among adults with primary youth-onset anxiety disorders.

OBJECTIVES: It is of potentially great public health importance to determine whether youth-onset anxiety disorders are associated with the increased prevalence of subsequent bipolar I disorder (BD) among adults, and to identify risk factors for BD in this population.

METHODS: The 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions was used to identify respondents with social phobia, panic disorder, or generalized anxiety disorder that onset in youth (<19 years) and was not preceded by a major depressive, manic, or mixed episode (N=1571; 572 males, 999 females). The prevalence of BD among subjects with, versus without, these youth-onset anxiety disorders was examined. Variables that could be associated with the increased risk of BD among subjects with youth-onset anxiety disorders were examined, including conduct disorder, youth-onset substance use disorders (SUD), and family history of depression and/or alcoholism. Analyses were computed separately for males and females.

RESULTS: The prevalence of BD was significantly greater among adults with, versus without, primary youth-onset anxiety disorders for both males (15.9% vs 2.7%; chi2=318.4, df=1, p<0.001) and females (13.8% vs 2.9%; chi2=346.2, df=1, p<0.001). Youth-onset anxiety disorders remained significantly associated with BD after controlling for interceding major depression, and this was true for each of the specific anxiety disorders examined. Among males with youth-onset primary anxiety disorders, conduct disorder and loaded family history of depression were associated with significantly increased risk of BD. Among females, conduct disorder and loaded family history of alcoholism were associated with significantly increased risk of BD.

CONCLUSIONS: The prevalence of BD was elevated among subjects with youth-onset primary anxiety disorders, particularly if comorbid conduct disorder was present. Future studies are needed to confirm these findings prospectively, and to develop preventive strategies for populations at risk.