Associations between endometriosis and depression and/or anxiety : a population-based study using symptomatic and asymptomatic endometriosis patients

Objectives: Endometriosis is a painful and inflammatory condition affecting approximately 10% of female people. The association between endometriosis, depression, and anxiety is well known, but the mechanism driving it, and its potential effects on treatment, remain elusive. This thesis aims to: 1) Determine the prevalence of depression and/or anxiety in a pathologically-confirmed endometriosis cohort and estimate how these co-morbid conditions may affect treatment outcomes; and 2) Estimate the depression and/or anxiety risk in three different groups of endometriosis or pelvic pain patients to better understand the mechanism between endometriosis and mental health. Methods: Population-based administrative databases in British Columbia were linked from 1998 to 2017. The prevalence of depression and/or anxiety was determined in those with pathologically-confirmed endometriosis. Descriptive statistics and logistic regression were used to estimate effects on treatment outcomes following surgery, such as physician visits, prescriptions, and reoperations. Then the cohort was split into three groups based on their symptomology and diagnoses (Group 1 – symptomatic endometriosis patients, Group 2 – symptomatic patients without endometriosis, and Group 3 – asymptomatic endometriosis patients). Cox proportional hazards models were used to estimate each group’s depression and/or anxiety risk. Results: Pathologically-confirmed endometriosis patients had a 15.8% prevalence of depression and/or anxiety. Patients with depression and/or anxiety had a higher odds of having a reoperation, visiting a physician for pelvic pain, and being prescribed hormonal medications and prescription-level analgesics. When comparing our three groups, Group 2 had a higher risk of depression and/or anxiety compared to Group 1. Additionally, Group 3 had no significant difference in risk compared to Group 1. This confirms that both the painful symptoms of endometriosis and its inflammatory nature could be contributing to the risk for depression and/or anxiety. Conclusion: Our results support and contribute to the growing evidence that endometriosis is a systemic condition. We observed a high prevalence of depression and/or anxiety in this cohort and higher odds of reoperation and pain-related health services use in these individuals. Further, both painful symptoms and inflammation appear to be factors in the risk for depression and/or anxiety. Therefore, systemic care, with consideration for mental well-being, should be part of endometriosis treatment.