Incidence of Depression Twice as High in People with Diabetes

In Germany, more than 6.5 million people have diabetes, most of them type 2. Of these, an estimated 800,000 people also suffer from a depression that requires treatment. “The incidence of depression among people with diabetes is twice as high as it is for the nondiabetic population,” said Professor Bernd Kulzer. He holds a diploma degree in psychology, is speaker of the Diabetes and Psychology Working Group of the German Diabetes Association (DDG), and is a DZD project partner. At the press conference on November 30, 2017 he spoke about the topic “When it gets dark - why depression in diabetes is a massive problem”.

English translation of Professor Bernd Kulzer's statement at the press conference:

Depression is an important and pressing issue in diabetes therapy, because there are interrelationships between the two diseases. Every third diabetic patient is under increased psychological stress and is at risk of developing depression, and every eighth to tenth person with diabetes suffers from clinical depression. This makes depression about twice as common as in the general population. In total, there are currently over 800,000 people in Germany with diabetes who also suffer from depression. On the other hand, depression in people without diabetes increases the likelihood of developing type 2 diabetes due to reduced insulin sensitivity. Therefore, depression is an important risk factor to be considered in the prevention of diabetes.

All in all, the effects of depression and increased depressiveness are extremely negative - on the patient, on medical professionals who treat diabetes, and also on society which seeks to support the patient. Depression makes diabetes treatment more difficult: it leads to poorer blood glucose levels, increases the risk of sequelae and worsens the prognosis of diabetes. The effects of depression in diabetes are also so serious because diabetes therapy is almost entirely in the hands of the patient and has to be implemented as well and successfully as possible by the patient on a daily basis. This is all the more difficult if depression causes a reduction in drive and patients have less energy to take care of their diabetes. The tendency to ruminate and a feeling of indifference can also lead to postponement or omission of decisions such as measuring blood sugar or physical activity. Since in depression there is no positive outlook for the future and negative thoughts predominate, many affected people also question the sense of diabetes therapy ("Why, for what purpose?"). Depression leads to poorer blood glucose levels and an unhealthy lifestyle characterized by lack of exercise and uncontrolled eating habits. This has consequences, because people with diabetes and depression have significantly more sequelae than diabetes patients without depression. In addition to the treatment costs for both diseases, it is particularly the increased costs for the treatment of the sequelae that make the costs for depressive diabetes patients about 50% higher in comparison.

Another previously underestimated consequence of depression in diabetes is the increased mortality rate. The group led by Kruse (1) recently concluded in a comparative study of previous studies on this topic (meta-analysis) that depression doubles the mortality risk in people with diabetes. This is probably due to two factors. The risk of suicide is higher in depressive people, which is more evident in diabetes than in depressive people without diabetes.  A recent study (2) showed that the risk of suicide in diabetes is about 50% higher compared to the general population; especially younger men with type 1 diabetes are at risk. Extrapolated to Germany, more than 2 people with depression and diabetes commit suicide every day, more than 800 people a year – far too many!
However, the increased mortality rate of depressive people with diabetes is mainly due to the intrapsychic chronic long-term stress caused by depression, which via the activation of the hypothalamic-pituitary-adrenal (HPA) axis leads to an increase in inflammatory processes (inflammation) in the large and small blood vessels, which are particularly at risk in diabetes anyway. Thus, depression in people with diabetes is a kind of "accelerator" for vascular damage that leads to the sequelae of diabetes. A group of researchers from Bad Mergentheim and Düsseldorf, working in research projects of the German Center for Diabetes Research (DZD), found that a behavioral therapy program for people with increased depression reduced the stress burden of diabetes. It also improved metabolic control, reduced inflammatory processes in the blood vessels, and prevented the development of clinical depression (3,4,5).

Prior to therapy, however, depression must be diagnosed, and this still occurs far too rarely in people with diabetes. In the international DAWN2 study, only 30% of all patients in Germany stated that they had been questioned by their doctor about depression; in total, more than 50% of all cases of depression in diabetes have not yet been detected (6). For those affected, the first warning signs are when diabetes therapy becomes a burden and costs more energy than before. The incidence of sequelae and severe hypoglycemia also increase the risk of depression. For self-assessment as to whether a depression is present, the German Health Passport Diabetes contains a short questionnaire with 5 questions (WHO-5), which patients can use to check for depression and ask a doctor for further clarification. For physicians, the guideline "Psychosocial and Diabetes", which is also available in an edition for the medical practice, contains important information on the diagnosis and therapy of depression in diabetes (7). Questionnaires for the screening and diagnosis of depression as well as a list of all specialized psychologists for diabetes in the DDG, who have completed a special diabetological training, can be found on the website of the Diabetes and Psychology Working Group. (

It is very much to be welcomed that psychotherapeutic care for diabetes patients with co-morbid mental disorders such as depression will improve in the future. This was ensured at the beginning of this year at the 30th German Psychotherapists' Day in Hannover, which by a large majority extended the further training course curriculum for psychological psychotherapists with an additional training course in special psychotherapy for diabetes ). Experts from the German Diabetes Association (DDG) and the German Society of Endocrinology (DGE), who had made a strong case for this extension, welcome the decision, also pointing out the poor care situation of people with diabetes and depression.

About Bernd Kulzer:
Professor Dipl.-Psych. Bernd Kulzer from the Diabetes Center Bad Mergentheim is head of the Research Institute of the Diabetes Academy Bad Mergentheim (FIDAM), lecturer at the University of Bamberg, speaker of the Diabetes and Psychology Working Group of the DDG and scientist at the German Center for Diabetes Research.

(1) Hofmann M, Köhler B, Leichsenring F, Kruse J.(2013). Depression as a Risk Factor for Mortality in Individuals with Diabetes: A Meta-Analysis of Prospective Studies. Al Naggar RA, ed. PLoS ONE;8(11):e79809. doi:10.1371/journal.pone.0079809.

(2) Wang B, An X, Shi X, Zhang JA. (2017). Suicide risk in patients with diabetes: a systematic review and meta-analysis. Eur J Endocrinol October 1, 177 R169-R181

(3) Hermanns N, Schmitt A, Gahr A, Herder C, Nowotny B, Roden M, Ohmann C, Kruse J,
Haak T, Kulzer B. (2015). The effect of a diabetes-specific cognitive behavioral treatment program
(DIAMOS) for patients with diabetes and subclinical depression: results of a randomized
controlled trial. Diabetes Care; 38: 551-560
(4) Schmitt, A., Reimer, A., Ehrmann, D., Kulzer, B., Haak, T., Hermanns, N., (2017). Reduction of depressive symptoms improved glycaemic control: secondary results from the DIAMOS study. J. Diabetes Complications 2017 Aug 9. pii: S1056-8727(17)30538-X. doi: 10.1016/j.jdiacomp.2017.08.004

(5) Herder, C., Schmitt, A., Budden, F., Reimer, A., Kulzer, B., Roden, M., Haak, T., Hermanns, N., (2017). Association between pro- and anti-inflammatory cytokines and depressive symptoms in patients with diabetes – potential differences by diabetes type and depression scores. Transl. Psychiatry (in press)

(6) Kulzer B, Lüthgens B, Landgraf R, et al. (2015). Diabetesbezogene Belastungen, Wohlbefinden und Einstellung von Menschen mit Diabetes. Deutsche Ergebnisse der DAWN2™-Studie. Diabetologe 11(3):211-218

 (7) Kulzer B, Albus C, Herpertz S, Kruse J, Lange K, Lederbogen F, Petrak F. (2013). Psychosoziales und Diabetes. Diabetologie und Stoffwechsel 8(3):198-242; 8(4): 292-324