Depression and endometriosis

August 5, 2019

Chronic pain appears to play a major role in the relationship between endometriosis and depression, according to a recent meta-analysis.

The connection between endometriosis and depression is mostly determined by chronic pain, according to a systematic review and meta-analysis in the journal PLOS One. The review also concluded that this association may be modulated by individual and context vulnerabilities.

“Awareness of the complex relationship between endometriosis and depressive symptoms informs tailored care and patient-centered research outcomes,” wrote the Brazilian authors. The authors searched PubMed, Embase, PsychINFO and the Cochrane Library through September 2017.

Eligibility criteria were full-text original articles that included quantitative data about depressive symptoms or depression, comparison of women with and without endometriosis, or women with endometriosis with and without pelvic pain. Most of the included 27 studies, which totalled 99,736 women, reported cross-sectional findings and were published over the last decade. Eighty percent of the studies were from either Europe or North America. The median number of subjects per study was 100, ranging from 39 to 75,140.

The analysis found higher levels of depression among women with endometriosis versus healthy controls (standardized mean difference [SMD] 0.22; 95% confidence interval [CI]: 0.13 to 0.32). However, the heterogeneity in the analysis (I2 = 68%) was not explained by any of the moderating variables.The SMD was used as effect size because depressive symptoms are measured with different scales and, often, as continuous data. However, the heterogeneity in the analysis (I2 = 68%) was not explained by any of the moderating variables.

When considering only healthy controls, a larger endometriosis-depression effect was found, according to 11 studies (SMD 0.49; 95% CI: 0.24 to 0.73; I2 = 69%). In addition, endometriosis patients reporting pelvic pain had significantly higher levels of depression, as opposed to those without pain, according to four studies (SMD 1.01; 95% CI: 0.71to 1.31; I2 = 0%). 

But no significant difference was found between women with both pelvic pain and endometriosis and those with pelvic pain but without endometriosis, according to 11 studies (SMD -0.11; 95% CI: -0.25 to 0.04; I2 = 0%).

“Clinicians who assist women with chronic pain and known or suspected endometriosis need awareness of the association with depressive symptomatology and its complex background in order to provide tailored and patient-centered management,” the authors wrote.

They noted, however, that the link between chronic pain and depression may reduce the effect of treatments and intensify individual and social vulnerabilities.

Nonetheless, timely detection and treatment of depressive symptoms can improve quality of life and physical symptoms, regardless of objective physiologic changes; therefore, screening for psychiatric symptoms in women with endometriosis has been advocated.

The review findings suggest that these women with chronic pain are candidates for such screening. However, the primary limitation of the review is “reliance on cross-sectional data, which does not allow for inference about directionality or causality between endometriosis and depressive symptoms,” the authors wrote.

Pragmatic guidelines to manage endometriosis patients with depressive symptoms would be helpful, according to the authors, “because screening programs for depression are unlikely to be effective without structured care.”

Meanwhile, as recommended by the United Kingdom’s National Institute for Health and Clinical Excellence (NICE), clinicians can ask women with endometriosis two questions: 1) During the last month, have you often been bothered by feeling down, depressed or hopeless? 2) During the last month, have you often been bothered by having little interest or pleasure in doing things?

In fact, it could be argued that mental health should be the No. 1 core outcome measure of endometriosis trials, according to the authors, and depression should be studied as both a treatment target and as potential harms associated with treatment interventions.

The cost-effectiveness of screening and care is also an important component because both endometriosis and depression weigh heavily on the healthcare system, especially with pain symptoms.