Development and vulnerability: new perspectives for anxiety disorders

Lifetime comorbidities between phobic disorders and major depression in Japan: results from the World Mental Health Japan 2002-2004 Survey

BACKGROUND

Although often considered of minor significance in themselves, evidence exists that early-onset phobic disorders might be predictors of later more serious disorders, such as major depressive disorder (MDD). The purpose of this study is to investigate the association of phobic disorders with the onset of MDD in the community in Japan.

METHODS

Data from the World Mental Health Japan 2002-2004 Survey were analyzed. A total of 2,436 community residents aged 20 and older were interviewed using the WHO Composite International Diagnostic Interview 3.0 (response rate, 58.4%). A Cox proportional hazard model was used to predict the onset of MDD as a function of prior history of DSM-IV specific phobia, agoraphobia, or social phobia, adjusting for gender, birth-cohort, other anxiety disorders, education, and marital status at survey.

RESULTS

Social phobia was strongly associated with the subsequent onset of MDD (hazard ratio [HR]=4.1 [95% CI: 2.0-8.7]) after adjusting for sex, birth cohort, and the number of other anxiety disorders. The association between agoraphobia or specific phobia and MDD was not statistically significant after adjusting for these variables.

CONCLUSIONS

Social phobia is a powerful predictor of the subsequent first onset of MDD in Japan. Although this finding argues against a simple neurobiological model and in favor of a model in which the cultural meanings of phobia play a part in promoting MDD, an elucidation of causal pathways will require more fine-grained comparative research.

Comorbidity of mood and anxiety disorders

This article reviews data on the prevalence of panic, social phobia, generalized anxiety, and posttraumatic stress disorder, and research documenting the comorbidity of these disorders with major depression (MDD). These anxiety disorders are frequently comorbid with MDD, and 50-60% of individuals with MDD report a lifetime history of one or more of these anxiety disorders. The anxiety disorders are also highly correlated with one another, and approximately one-quarter to one-half of individuals with each of the anxiety disorders report a lifetime history of an alcohol or substance use disorder. Anxiety disorders rarely exist in isolation, with several studies reporting that over 90% of individuals with anxiety disorders have a lifetime history of other psychiatric problems. Implications for research are discussed, including the potential benefit of using combined categorical and dimensional rating scale approaches in future genetic, biochemical, neuroimaging, and treatment studies. The clinical implications of the findings are also discussed, and the results of recent clinical trials summarized. Available data suggests selective serotonin reuptake inhibitors are the first-line pharmacological treatment for these disorders, and that newer serotonin and norepinephrine reuptake inhibitors show significant promise, especially for comorbid cases. Comorbidity among depression and anxiety disorders is associated with greater symptom severity, and a considerably higher incidence of suicidality. Increased public awareness about these disorders and the availability of effective treatments is sorely needed.