Adult patients with diabetes who trust their medical provider and feel included in treatment decisions are significantly more likely to take and maintain a newly prescribed antidepressant medication, according to a new study in the Journal of General Internal Medicine.

The study, conducted by researchers at the Kaiser Permanente Division of Research and the University of Washington, School of Medicine, included 1,500 patients with long-standing diabetes, who were prescribed antidepressants.

"In patients with diabetes, depression has been linked to poor self-management and greater risk of diabetic complications including heart disease, dementia, and early mortality," said Andrew Karter, PhD, research scientist at Kaiser Permanente and senior author of the study. "Therefore, care providers believe that adherence to prescribed antidepressants is an important aspect of diabetes care. It is striking how strongly providers' relationships with their patients, particularly establishing trust and the use of shared decision-making, influenced whether patients became ongoing users of the medications prescribed for depression."

Patients with diabetes who were prescribed an antidepressant medication but did not feel included in treatment decisions were more than twice as likely to never fill the prescription. Patients who felt less trust in their provider were also one-third more likely to never refill their prescription after it was first dispensed and to have poor medication adherence during the 12 months after the initial prescription.

For this study, participants rated the quality of communication with their primary care provider during the preceding 12 months. While 96 percent of the patients filled their new antidepressant prescription at least once, rates of never filling were over double (6.1 percent vs. 2.7 percent) among patients who felt less involved in decision-making compared to those who felt more involved. Shared decision-making also was associated with better adherence later in the course of antidepressant treatment, albeit to a lesser degree, suggesting that patients' perceptions of involvement in clinical decisions may have particular significance for adherence in the initial stages of new antidepressant treatment.

"These findings build on previous work in the Diabetes Study of Northern California (DISTANCE) cohort, in which we observed lower adherence to antidepressant medications for patients with limited health literacy," said lead author Amy Bauer, MD, of the University of Washington School of Medicine. "Because the quality of provider communication is potentially modifiable, this serves as a promising target for interventions to improve adherence and therefore help patients get an adequate course of antidepressant therapy. Engaging patients in their care by fostering trust and encouraging shared decision-making is an important part of the therapeutic process that physicians can promote."

For over a decade, DISTANCE has evaluated the quality of diabetes care and identified reasons for observed health disparities. It draws upon a diverse sample of over 20,000 Kaiser Permanente Northern California adult members with diabetes aged 30 to 75 years.