Post-traumatic stress disorder and medication adherence: results from the Mind Your Heart study

Background: Patients with post-traumatic stress disorder (PTSD) are at increased risk for adverse outcomes from comorbid medical conditions. Medication non-adherence is a potential mechanism explaining this increased risk.

Methods: We examined the association between PTSD and medication adherence in a cross-sectional study of 724 patients recruited from two Department of Veterans Affairs Medical Centers between 2008 and 2010. PTSD was assessed using the Clinician Administered PTSD Scale. Medication adherence was assessed using a standardized questionnaire. Ordinal logistic regression models were used to calculate the odds ratios (ORs) for medication non-adherence in patients with versus without PTSD, adjusting for potential confounders.

Results: A total of 252 patients (35%) had PTSD. Twelve percent of patients with PTSD reported not taking their medications as prescribed compared to 9% of patients without PTSD (unadjusted OR 1.85, 95% CI 1.37-2.50, P<0.001). Forty-one percent of patients with PTSD compared to 29% of patients without PTSD reported forgetting medications (unadjusted OR 1.90, 95% CI 1.44-2.52, P<0.001). Patients with PTSD were also more likely to report skipping medications (24% versus 13%; unadjusted OR 2.01, 95% CI 1.44-2.82, P<0.001). The association between PTSD and non-adherence remained significant after adjusting for demographics, depression, alcohol use, social support, and medical comorbidities (adjusted OR 1.47, 95% CI 1.03-2.10, P=0.04 for not taking medications as prescribed and 1.95, 95% CI 1.31-2.91, P=0.001 for skipping medications).

Conclusions: PTSD was associated with medication non-adherence independent of psychiatric and medical comorbidities. Medication non-adherence may contribute to the increased morbidity and mortality observed in patients with PTSD.