Depression is twice as common in people with DM than in the general population, and it’s associated with poorer medical outcomes, including worse glycemic control, increased risk for DM-related complications, and early mortality.

The increased prevalence of depressive disorders in diabetes has been attributed to a variety of potential factors, including the psychologic and psychosocial impact of diabetes, certain common genetic susceptibility determinants, common pathophysiologic abnormalities, and microvascular brain lesions. The presence of diabetes-associated medical comorbidity may be a significant contributor, as well.

In the approach to patients with MDD who also have diabetes, a number of interventions have been explored, including those that fall under the headings of collaborative care, pharmacologic interventions, and psychologic treatments, such as CBT.

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With respect to CBT, randomized clinical trials have shown that face-to-face, protocol-driven CBT interventions are effective for treating depression in patients with DM; however, less is known about iCBT.

In a recent study by Newby and colleagues, a generic clinician-guided iCBT program for MDD in people with type 1 or 2 DM was evaluated in a randomized clinical trial. The intervention was a generic 6-lesson iCBT delivered over 10 weeks in people with MDD and DM. Patients were recruited online and randomly assigned to an iCBT program with therapist support provided by phone and email (n=42) or to a treatment as usual (n=49). A total of 27 participants (66%; 27/41) completed the iCBT program. Results at 3 months indicated that the generic iCBT program for the treatment of depression was superior to treatment as usual in reducing depression, diabetes-related distress, anxiety, and general distress, and in improving mental well-being for people with comorbid DM and MDD.

Overall, this group’s findings were consistent with those of other studies showing that CBT for depression leads to improved depression outcomes but has a limited effect on HbA1c (glycated hemoglobin) levels. The authors felt that additional research will be needed to determine the most effective ways to engage people with comorbid DM and depression in iCBT programs.