Chicken or the egg: a new perspective on endometriosis and depression

For a long time, endometriosis was seen in medical thinking exclusively as a gynaecological problem, focusing mainly on painful menstruation, infertility and chronic pelvic pain. In recent years, however, a growing body of research has highlighted that the disease is much more complex and is often associated not only with physical but also with mental health problems, in particular depression. A study published in 2025 (Mormile et al) explores the relationship between these two conditions from a new perspective: not simply as co-morbidities, but as potentially common phenomena.

The authors hypothesise that endometriosis and depression are not merely co-occurring conditions with a purely psychological link, for example through depression resulting from chronic pain and quality of life deterioration, but that there may be a genuine causal link at a biological level. In their opinion, the risk between the two diseases is not unidirectional but mutually reinforcing: endometriosis may predispose to depression, but at the same time women with depression may also have a higher prevalence of endometriosis.

The key to the explanation is a common immunological network in which two cell types play a prominent role: myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs). MDSCs are cells that are involved in immune system inhibitory mechanisms but in some cases can also enhance inflammatory processes. In contrast, the role of Treg cells is precisely to regulate the immune response and, when overactive, to control inflammation. The researchers believe that women with endometriosis typically have an over-abundance of MDSCs and a reduced function of Treg cells , which may be responsible not only for inflammatory gynaecological symptoms but also for the development of mood disorders.

This approach gives a new understanding of the relationship between the two diseases. Depression should therefore not only be understood as a psychosocial consequence, but also as a condition resulting from an imbalance in the immune system, which is partly biologically determined. The authors emphasise that further studies are needed in order to map precisely the common pathophysiological pathways underlying both diseases. Such research not only contributes to theoretical knowledge, but also has practical implications: if there is indeed a common underlying mechanism, it may be possible to develop a targeted therapy that treats both the physical symptoms of endometriosis and the depressive state.

The conclusion of the study is clinically important: if the hypothesised biological link is confirmed, women with endometriosis should be proactively counselled about their risk of developing depression. This would not only help early detection but also ensure that they receive the necessary psychological and medical support in a timely manner. Such an approach could help to ensure that the treatment of endometriosis in the future is not just a gynaecological but a truly holistic approach.

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