Polycystic ovary syndrome and psychiatric disorders: Co-morbidity and heritability in a nationwide Swedish cohort.

Polycystic ovary syndrome (PCOS) is an endocrine disorder affecting 5-15% of reproductive-aged women and characterized by high levels of circulating androgens. Given that androgens have been implicated in the aetiology of several psychiatric disorders, it was hypothesized that women with PCOS have high risk for psychiatric comorbidity. We aimed to investigate this risk amongst women with PCOS, as well as in their siblings, to elucidate if familial factors underlie any potential associations. Using the Swedish national registers, we identified all women diagnosed with PCOS between 1990 and 2013 (n=24,385), their full-siblings (n=25,921), plus matched individuals (1:10/100) from the general population and their full-siblings. Psychiatric disorder diagnoses were identified including schizophrenia, bipolar disorder, depressive and anxiety disorders, eating disorders, personality and gender identity disorder, autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), tics, attempted and completed suicide. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression and adjusted ORs (AOR) were determined by adjustment for comorbid psychiatric disorders. Overall, women with PCOS had an increased odds of having at least one psychiatric disorder (OR=1.56 [95CI%, 1.51-1.61]). Crude ORs showed associations with nearly all psychiatric disorders included in this study. Following adjustment for comorbid psychiatric disorders, women with PCOS were still at a significantly increased risk for bulimia, schizophrenia, bipolar disorder, depressive and anxiety disorders, personality disorders, with the highest AORs for ASD (AOR=1.55 [95%CI, 1.32-1.81]) and tics (AOR=1.65 [95%CI, 1.10-2.47]). Significantly higher AORs were found for ASD in both brothers and sisters of women with PCOS, and for depressive, anxiety, and schizophrenia spectrum disorders in the sisters only. Notably, the crude ORs for attempted suicide were 40% higher in women with PCOS and 16% higher in their unaffected sisters. However, the AORs were greatly attenuated indicating that underlying psychiatric comorbidity is important for this association. Women with PCOS had higher risks for a range of psychiatric disorders not shown before. Elevated risk in their siblings suggests shared familial factors between PCOS and psychiatric disorders. This study is an important first step towards identifying the underlying mechanisms for risk of psychiatric disorders in women with PCOS. Health professionals treating women with PCOS should be aware that these patients - as well as their family members - are important targets for mental health care.