Depression and diabetes mellitus are a detrimental burden on global health with severe impacts on the individual quality of life. Type 2 diabetes, a chronic, non-communicable disease with severe long-term complications, affects 9% of the world’s population. One in twenty persons worldwide suffers from depressions. The combination of the two diseases makes matters even worse. The probability of a diagnose with depression is five times higher in diabetics than in the non-diabetic population.

Last year, my colleague Carola Deischinger, a PhD student at the Medical University of Vienna who is like me interested in gender medicine, and I analyzed patients diagnosed with diabetes mellitus (DM) and with a major depressive disorder (MDD). We had the opportunity to work with a large data set, spanning 17 years (1997 to 2014) of medical data from the whole Austrian population. The anonymized data set includes approximately nine million patients and 4,5000,000 hospital stays.

As stated above, it is already known that patients suffering from diabetes also have an increased depression risk. We wanted to check if there is a gender difference, and to analyze the results in detail, especially the impact of diabetes on depression over a lifetime. We therefor extracted data of 123,232 patients with diabetes mellitus and compared them with non-diabetics.

Our paper, recently published in BMJ Open Diabetes Research & Care, shows that diabetic women had an over twofold risk of being diagnosed with a major depression than women without diabetes. This risk was significantly lower in diabetic men. My co-authors and I discussed possible reasons for that difference. We performed a sensitivity analysis and identified overweight obesity and alcohol dependence as the strongest influencing factors.

Our paper shows for the first time that type 2 diabetes is an even greater risk factor for depression in women than in men. The results should influence the clinical practice: Overweight diabetic women—with or without cardiovascular disease—should be even more carefully assessed and monitored for depression.