Depression in adults with type 2 diabetes: the role of adherence, body mass index, and self-efficacy.

Considerable evidence links depression with the development and worsening of diabetes, but the factors contributing to this link have not been established. The authors examined the role of adherence, body mass index (BMI), and self-efficacy. Adult patients with Type 2 diabetes (N = 56) completed self-report measures of diet and exercise adherence, diet and exercise self-efficacy, and depression. BMI was obtained from medical records. Path and mediation analyses indicated that both adherence and BMI independently contributed to self-efficacy. Self-efficacy mediated both the association between adherence and depression and the association between BMI and depression. These findings are consistent with the proposal that lower self-efficacy in reaction to adherence failure and higher BMI contributes to depression in adults with diabetes.