A “syndemic” relationship: Managing depression and diabetes

The new term “syndemic” is being used to describe two common conditions which appear together, each worsening the prognosis of the other. With major depression and diabetes, we have such a situation, Norman Sartorius (Geneva, Switzerland) told at a WPA session on physical comorbidities of mental ill-health. It was in this context, that investigators in 14 countries collaborated on the INTERPRET DD study.

Patients with type 2 diabetes who were visiting a clinic and agreed to take part were examined by a psychiatrist using the Mini International Neuropsychiatric Interview (MINI-6) and other measures. In total, 2783 patients were enrolled. They had a mean age of 54 and had diabetes for almost 9 years, half being on insulin. Around half were recorded as having a complication of diabetes.

The proportion of patients who had a current major depressive disorder (MDD) according to the MINI was 10.6% (i.e., 294 cases). A further 18% of diabetic patients had a PHQ-9 score higher than 9, indicating a level of depressive symptoms that was high but not sufficient to justify a diagnosis of depression.

The proportion of type 2 diabetes patients with current MDD was 10.6%

Yet only 5% of patients with MINI-diagnosed depression (14 out of 294) had a mention of MDD in their notes. And in only 11 cases (3.7%) did the notes mention treatment.

Should we be alarmed?

INTERPRET DD confirms a high level of depression among people with diabetes, and that itself is cause for concern. The very low rate at which depression is recorded in the diabetes clinic notes may reflect lack of awareness of the problem. An alternative explanation is that the under-recording reflects a reluctance to mention a potentially stigmatizing diagnosis, Professor Sartorius said.  But his suspicion is that those working in diabetes clinics have not been looking for the problem. And if that is true we should be worried – for a range of reasons.

As outlined by Gerhard Heinze Martin (Universidad Nacional Autonoma de Mexico), untreated depression can result in poor self-care, poor communication with health providers, and poor treatment-adherence, leading to inadequate control of glycemia.¹

Untreated depression can result in poor self-care, poor communication with health providers, and poor treatment-adherence – leading to inadequate control of glycemia

Earlier in the session, Giovanni Girolamo (IRCCS, Brescia, Italy) provided an update on the World Mental Health Survey Initiative which has been investigating comorbid physical and mental ill-health across 28 countries using rigorous, standardized sampling techniques and interviewer training.²

It seems that the rate of MDD among people with diabetes is around twice that seen in people without diabetes. The higher rate of mental ill-health could be a consequence of developing the physical condition, or it could be a cause of it.

The rate of MDD among people with diabetes is around twice that seen in people without diabetes

There is a strong case for investing in the psychosocial care of people with diabetes – since they are at greater than average risk of developing psychiatric disorders. All clinicians should be aware of associations and ensure that their patients are adequately screened and subsequently treated for these conditions as their impact alone or together can have a significant effect on the quality of life the patient experiences.