Psychiatric comorbidity among women with endometriosis: nationwide cohort study in Sweden.
BACKGROUND
Endometriosis is a common gynecologic condition affecting women of reproductive age. It has been linked with greater rates of depression and anxiety in small, cross-sectional, and clinical studies. Other studies have reported that women with endometriosis have increased risk of bipolar disorder. These reports suggest that psychiatric disorders might be more common among women with endometriosis, contributing to increased burden of mental ill-health in this population of women. However, this hypothesis has not been adequately studied.


OBJECTIVES
In this population-based study, we investigated the overall psychiatric comorbidity among women with endometriosis, and the role of familial liability.


STUDY DESIGN
Several Swedish national registers were linked and used to follow all women born in Sweden in 1973-1990 for diagnosed psychiatric disorders and endometriosis from age 14 years until year 2016. Sibling comparison analyses were performed in a subsample of 173,650 families.


RESULTS
After adjustment for birth characteristics and education, women with endometriosis had an increased risk of being later diagnosed with depressive-, anxiety and stress-related disorders, alcohol/drug dependence, and attention-deficit hyperactivity disorder compared with the general population and with their sisters without endometriosis. The adjusted hazard ratios ranged from 1.56 (95% confidence interval, 1.29-1.88) for depressive disorders to 1.98 (95% confidence interval, 1.34-2.93) for attention-deficit hyperactivity disorder in the sibling analysis. Also, women with previous affective psychotic disorders, depressive-, anxiety and stress-related disorders, eating disorders, personality disorders, and attention-deficit hyperactivity disorder were more likely to be later diagnosed with endometriosis. The adjusted hazard ratios ranged from 1.51 (95% confidence interval, 1.30-1.76) for depressive disorders to 1.93 (95% confidence interval, 1.47-2.52) for personality disorders.


CONCLUSION
These findings reveal a high degree of comorbidity between endometriosis and many psychiatric disorders that was not entirely explained by shared familial confounding. Clinical practice may consider psychosocial support to women with endometriosis and treating them from a multidisciplinary perspective.