Comorbid anxiety as a suicide risk factor among depressed veterans.

BACKGROUND: Depressive disorders greatly increase suicide risk; however, little is known about the contribution of comorbid anxiety disorders or anxiety symptoms to the risk of suicide death among depressed patients. We examined whether depressed veterans with comorbid anxiety had higher risks of suicide death.
METHODS: Using VA administrative databases we identified 887,859 patients with depression. We then used univariate and multivariate logistic regression, controlling for demographics and substance use disorders, to determine the odds ratios of completed suicide associated with individual comorbid anxiety disorders, the presence of any comorbid anxiety disorder, the prescription of an antianxiety medication, or the prescription of a high dose of an antianxiety medication.
RESULTS: In multivariate analyses, the odds of completed suicide were significantly increased for patients with panic disorder (OR 1.26, 95% CI: 1.04-1.53), generalized anxiety disorder (OR 1.27, 95% CI: 1.09-1.47), and anxiety disorder, not otherwise specified (OR 1.25, 95% CI: 1.12-1.38). The odds of completed suicide were also greater among patients who received any antianxiety medication (OR 1.71, 95% CI: 1.55-1.88), and were further increased among those who received high dose treatment (OR 2.26, 95% CI: 1.98-2.57). Odds of completed suicide were decreased among patients with comorbid posttraumatic stress disorder (OR 0.87, 95% CI: 0.77-0.97), and there was no statistically significant relationship between social phobia, obsessive-compulsive disorder, and all other anxiety disorders and suicide.
CONCLUSIONS: These findings emphasize the importance of comorbid anxiety disorders and symptoms in increasing suicide risk among depressed patients and may inform suicide prevention efforts among these patients. (c) 2009 Wiley-Liss, Inc.