Depression and anxiety in Type 2 Diabetes

By Prof Sergio Starkstein, School of Psychiatry UWA, and Fremantle Hospital

Type 2 Diabetes coupled with anxiety and depression is an untoward combination, increasing the risk of health complications. How can doctors screen for this combination and is it simple?

Prof Sergio Starkstein

The prevalence of depression in type 2 diabetes is twice that in the general population. Moreover, patients with diabetes and depression have higher rates of diabetic complication and poor glycaemic control than patients with diabetes but no depression. They have more severe vascular disease, greater physical disability and higher mortality than patient with diabetes but no lifetime depression. Even the presence of sub-clinical depression is associated with adverse outcomes.

The cause of depression in diabetes seems to be multifactorial; but aetiological factors may include the stress and burden of managing a complex disease associated with chronic complications.

When depression occurs before the onset of diabetes, there is poor glycaemic control despite intensive diabetes management, as well as major vascular complications. This has been attributed to lower adherence to medication regimens and detrimental lifetime factors. It is important, therefore, to enquire about lifetime depression histories and these patients probably benefit from depression screening at intervals.

Anxiety affects up to 40% of patients with type 2 diabetes, and depressive and anxious symptoms occur together in about 17% of these patients. This comorbidity is associated with adverse psychological outcomes, poor health behaviour and worse glycaemic control.

Based on these findings, it is suggested that earlier identification and treatment of long-standing depression and anxiety, reduces the risk of more severe psychopathology, worse glycaemic control and associated risk for health complications.

The PHQ-9 is a self-assessed questionnaire for depression, whereas the GAD-7 is a self-assessed questionnaire for anxiety, which were validated in diabetes. Both may be completed in less than 10 minutes in the waiting room and may provide valuable information to the GP regarding the emotional status of the patient.

There are new instruments, soon to be available to the GP, that combine the main items of the PHQ-9 with items from instruments to specifically screen for anxiety in type 2 diabetes. These instruments are short and can be easily completed in the waiting room.

They provide information on the diagnostic category of mixed anxiety-depression, which is most frequent in diabetes and has the strongest predictive value. Recent studies have identified a sub-group with major depression and anxiety which was associated with a higher incidence of coronary heart disease and cardiovascular mortality – future studies may demonstrate the usefulness in monitoring response to psychiatric treatment and assessment of cardiovascular risk.

Key Points

  • Depression and anxiety can worsen outcomes in Type 2 Diabetes.
  • GPs can use screening tools to assess both problems in diabetes.
  • Researchers may find that screening for associated cardiovascular risk in affected patients is a good idea.

Disclaimer: Please note, this website is not a substitute for independent professional advice. Nothing contained in this website is intended to be used as medical advice and it is not intended to be used to diagnose, treat, cure or prevent any disease, nor should it be used for therapeutic purposes or as a substitute for your own health professional’s advice. Opinions expressed at this website do not necessarily reflect those of Medical Forum magazine. Medical Forum makes no warranties about any of the content of this website, nor any representations or undertakings about any content of any other website referred to, or accessible, through this website.