Depression, anxiety, perceived stress, and their changes predicted medical adherence over 9 months among patients with coronary heart disease

OBJECTIVES Although effective medical treatments have proved to successfully improve prognoses and outcomes of patients with coronary heart disease (CHD), low adherence to treatments is still common among patients. Deleterious impact of psychological distress on medical adherence has been recognized; however, few studies examined the influence of change in psychological distress on attenuation in adherence. This study investigated whether three common manifestations of distress (depression, anxiety, and perceived stress) and their changes predicted decline in medical adherence among CHD patient over 9 months. DESIGN A three-wave longitudinal study. METHODS Participants were 255 CHD patients with a mean age of 63 years. Psychological distress, medication adherence, and specific treatment adherence were assessed at baseline, 3 months, and 9 months. Hierarchical regression analyses were conducted to examine the influences of psychological distress on medical adherence over 9 months. All models were adjusted for baseline medication or specific adherence, demographic, and medical covariates. RESULTS Baseline depression and its changes over time significantly predicted greater decline in both medication adherence (βs = .15-.20, ps < .05) and specific adherence (βs = -.21 to -.15, ps < .05). Anxiety showed a similar trend. For perceived stress, baseline and its change significantly predicted specific adherence over 9 months (βs = -.30 to -.23, ps < .01), but did not predict medication adherence at 3 and 9 months. CONCLUSIONS Findings underline the necessity of tracking various forms of psychological distress over time for CHD patients to promote medical adherence and further improve the disease prognosis.