Introduction: This study was done to examine the relationships (concurrent, prospective, and time-concordant) among major depressive disorder (MDD), depressive symptoms, and diabetes distress and glycemic control.
Methods: Type 2 diabetes patients were involved in this non-interventional study. Researchers assessed 506 patients for MDD (using Composite International Diagnostic Interview), depressive symptoms (using Center for Epidemiological Studies-Depression), and diabetes distress (Diabetes Distress Scale). The patients were also assessed for self-management, stress, demographics, and diabetes; all assessments were done at baseline, 9, and 18 months.
Cross-sectional relationships were explored with multilevel modeling; this was to examine the relationship of the 3 affective variables with A1c, as well as the prospective relationships of baseline variables with A1c changes over time and the time-concordant relationships with A1c.
Results: The 3 affective variables (MDD, depressive symptoms, and diabetes distress) were moderately intercorrelated; depressive symptoms and diabetes distress had a stronger relationship than either MDD and depressive symptoms or MDD and diabetes distress.
The cross-sectional multilevel modeling revealed that diabetes distress was significantly associated with A1c; neither depressive symptoms nor MDD showed a significant relationship with A1c.
The prospective analysis did not show an association between any of the 3 affective variables and A1c.
There was a significant time-concordant relationship between A1c and diabetes distress.
Conclusions: In patients with type 2 diabetes, there may be 2 conditions that are present when talking about “depression.” It could be that they have MDD and diabetes distress—with diabetes distress having a significant impact on A1c. More research on diabetes distress and MDD in the clinical setting is needed.
Commentary by Leonard E. Egede MD, MS
There is increasing awareness that emotional distress may have an independent effect on diabetes outcomes separate from depression. Recent studies have found that distress about living with diabetes may be as detrimental as depression. This article is one of the first to objectively evaluate this question. The authors compared three affective variables namely depressive symptoms, major depression and diabetes distress using validated questionnaires and found that all three variables are correlated. However, when they looked are correlations between each variable and glycemic control as measured by A1c, they found that only diabetes distress was significantly correlated with A1c. This raises the question whether diabetes distress is the major driver of the negative effect of depression on diabetes outcomes. Another recent study found that diabetes fatalism, which includes a measure of emotional distress, was associated with poor medication adherence and self-care in adults with diabetes even after controlling for depression . In combination, these studies suggest the need for better understanding of the role of emotional distress on health outcomes in people with diabetes.