Objective: To assess changes in health-related quality of life (HRQOL) and to determine whether co-occurring substance use and medical comorbidities were associated with worse HRQOL over a 1-year period in a naturalistic sample of patients with bipolar disorder.
Method: Patients enrolled in the Continuous Improvement for Veterans in Care: Mood Disorders (CIVIC-MD), a large prospective study from July 2004 to July 2006, completed baseline and follow-up assessments related to bipolar symptoms, comorbidity, and Short Form 12 HRQOL assessment at baseline and at 1 year later. Predictors of changes in HRQOL mental and physical health component scores were determined, using multivariable linear regression models and path analyses.
Results: Of 334 participants, the mean age was 49 years (standard deviation [SD] = 10.1 years; range = 21-78 years), 15.9% women, and 10.8% African American. At baseline, 19.8% reported hazardous drinking, 25.5% reported illicit drug use, and the mean number of co-occurring medical conditions was 2.70 (SD = 2.02). Illicit drug use was associated with worse mental HRQOL (beta = -2.01; p < .05), and increased number of medical comorbidities was significantly associated with worse physical HRQOL over time (beta = -0.71; p < .01). Depressive symptoms exhibited a strong and consistent influence on mental health scores over time, but path analyses revealed that they did not seem to mediate effects of comorbidities on lower HRQOL.
Conclusions: Illicit drug use and medical comorbidity negatively affected mental HRQOL over time, independent of bipolar symptoms, suggesting the need for interventions that address physical health and drug treatment needs for patients with bipolar disorder.