A Randomized Controlled Trial of Cognitive Behavioral Therapy for Adherence and Depression (CBT-AD) in Patients With Uncontrolled Type 2 Diabetes

OBJECTIVE To test cognitive behavioral therapy for adherence and depression (CBT-AD) in type 2 diabetes. We hypothesized that CBT-AD would improve adherence; depression; and, secondarily, hemoglobin A1c (A1C). RESEARCH DESIGN AND METHODS Eighty-seven adults with unipolar depression and uncontrolled type 2 diabetes received enhanced treatment as usual (ETAU), including medication adherence, self-monitoring of blood glucose (SMBG), and lifestyle counseling; a provider letter documented psychiatric diagnoses. Those randomized to the intervention arm also received 9-11 sessions of CBT-AD. RESULTS Immediately after acute treatment (4 months), adjusting for baseline, CBT-AD had 20.7 percentage points greater oral medication adherence on electronic pill cap (95% CI -31.14 to -10.22, P = 0.000); 30.2 percentage points greater SMBG adherence through glucometer downloads (95% CI -42.95 to -17.37, P = 0.000); 6.44 points lower depression scores on the Montgomery-Asberg Depression Rating Scale (95% CI 2.33-10.56, P = 0.002); 0.74 points lower on the Clinical Global Impression (95% CI 0.16-1.32, P = 0.01); and 0.72 units lower A1C (95% CI 0.29-1.15, P = 0.001) relative to ETAU. Analyses of 4-, 8-, and 12-month follow-up time points indicated that CBT-AD maintained 24.3 percentage points higher medication adherence (95% CI -38.2 to -10.3, P = 0.001); 16.9 percentage points greater SMBG adherence (95% CI -33.3 to -0.5, P = 0.043); and 0.63 units lower A1C (95% CI 0.06-1.2, P = 0.03) after acute treatment ended. For depression, there was some evidence of continued improvement posttreatment, but no between-group differences. CONCLUSIONS CBT-AD is an effective intervention for adherence, depression, and glycemic control, with enduring and clinically meaningful benefits for diabetes self-management and glycemic control in adults with type 2 diabetes and depression.