Predictors of persistence of comorbid generalized anxiety disorder among veterans with major depressive disorder.

OBJECTIVE: A limited number of randomized clinical trials show that efficacious pharmacologic treatments exist for comorbid major depressive disorder (MDD) and generalized anxiety disorder (GAD). The aims of this effectiveness study were to describe the impact of a depression care management intervention on the persistence of comorbid GAD symptoms in a sample of primary care patients with MDD and to identify risk factors for persistent GAD.

METHOD: Data were collected from April 2003 to September 2005 for the Telemedicine-Enhanced Antidepressant Management (TEAM) study, a multisite, randomized effectiveness trial targeting US Department of Veterans Affairs (VA) primary care patients with depression. Veterans aged 26.59-88.36 years received either the TEAM intervention or usual care in small VA community-based outpatient clinics. The TEAM care management intervention focused on optimizing antidepressant therapy through patient education and activation, symptom monitoring, adherence promotion, and side-effect management. Veterans who screened positive for MDD using the Patient Health Questionnaire-9 (based on DSM-IV criteria) and who met the Mini-International Neuropsychiatric Interview criteria (maintaining consistency with DSM-IV-TR) for comorbid GAD at baseline were selected for the present study (N = 168). The primary outcome was persistence of GAD at 6 months and 12 months. All predictors available in the TEAM study data that were described in the literature to be associated with influencing GAD outcomes were examined.

RESULTS: Persistence of depression was the strongest predictor of persistence of comorbid GAD at both 6 months (OR = 5.75; 95% CI, 2.38-13.86; P < .05) and 12 months (OR = 15.56; 95% CI, 6.10-39.68; P < .05). Although the TEAM intervention significantly reduced depression symptom severity, it was not significantly associated with GAD persistence. Insomnia was a significant protective factor for persistence of GAD at 6 months (OR = 0.66; 95% CI, 0.44-0.99; P < .05).

CONCLUSIONS: Early screening for presence of comorbid GAD among those with MDD may be valuable both for further research and for enhancing clinical management of GAD and MDD comorbidity.