The confusing tale of depression and distress in patients with diabetes: a call for greater clarity and precision.

Studies have identified significant linkages between depression and diabetes, with depression associated with poor self-management behaviour, poor clinical outcomes and high rates of mortality. However, findings are not consistent across studies, yielding confusing and contradictory results about these relationships. We suggest that there has been a failure to define and measure 'depression' in a consistent manner. Because the diagnosis of depression is symptom-based only, without reference to source or content, the context of diabetes is not considered when addressing the emotional distress experienced by individuals struggling with diabetes. To reduce this confusion, we suggest that an underlying construct of 'emotional distress' be considered as a core construct to link diabetes-related distress, subclinical depression, elevated depression symptoms and major depressive disorder (MDD). We view emotional distress as a single, continuous dimension that has two primary characteristics: content and severity; that the primary content of emotional distress among these individuals include diabetes and its management, other life stresses and other contributors; and that both the content and severity of distress be addressed directly in clinical care. We suggest further that all patients, even those whose emotional distress rises to the level of MDD or anxiety disorders, can benefit from consideration of the content of distress to direct care effectively, and we suggest strategies for integrating the emotional side of diabetes into regular diabetes care. This approach can reduce confusion between depression and distress so that appropriate and targeted patient-centred interventions can occur.