Association between depression risk and polycystic ovarian syndrome in young women: a retrospective nationwide population-based cohort study (1998–2013)

STUDY QUESTION: Is polycystic ovarian syndrome (PCOS) in women associated with the increasing incidence of depression in an East Asian population? SUMMARY ANSWER: Younger PCOS patients (aged 15-29 years), but not middle-aged patients, have an increased risk of depression in Taiwan. WHAT IS KNOWN ALREADY: During reproductive age, 6-10% of women have PCOS. Among them, ~40% experience depression, mostly at young ages. STUDY DESIGN, SIZE, DURATION: This is a retrospective population-based cohort study analysing depression risk in Taiwanese women using data from a nationwide database containing 1998-2013 data of nearly 1 million people. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included 15- to 50-year-old women newly diagnosed with PCOS during 1998-2013 from the Taiwan National Health Insurance Research Database as the PCOS cohort (n = 7684) and then randomly matched them 4 : 1 by sex, age and index year with women without PCOS as the comparison cohort (n = 30 736). We used multivariable Cox proportional hazard regression analysis to determine the association between PCOS and depression risk [hazard ratio (HR) with 95% confidence interval (CI)]. MAIN RESULTS AND THE ROLE OF CHANCE: The incidence of depression was higher in the PCOS group than in the comparison group (6.67 vs. 4.82 per 1000 person-years; adjusted HR = 1.28, 95% CI = 1.12-1.46). PCOS patients aged 15-29 years had a significantly higher depression risk (adjusted HR = 1.39, 95% CI = 1.18-1.65); no such significant association was noted among patients aged 30-39 years and 40-50 years. LIMITATIONS, REASONS FOR CAUTION: A history of malignancy, which may increase depression, could not be obtained for our study patients. Moreover, we could not obtain a family history of depression, a relevant risk factor for depression. Finally, the database has no records of body mass index, which may influence depression outcome. WIDER IMPLICATIONS OF THE FINDINGS: In Taiwan, younger PCOS patients (15-29 years), but not the middle-aged patients, have an increased risk of depression. Our findings provide vital information to patients, clinicians, the Taiwan Government and other developing Asian countries to improve the PCOS treatment strategies in the future. Routine screening for depression in PCOS patients may be implemented into the health practice. STUDY FUNDING/COMPETING INTEREST(S): This study was supported in part by the Taiwan Ministry of Health and Welfare Clinical Trial Center (MOHW108-TDU-B-212-133 004), China Medical University Hospital, Academia Sinica Stroke Biosignature Project (BM10701010021), MOST Clinical Trial Consortium for Stroke (MOST 107-2321-B-039 -004-), Tseng-Lien Lin Foundation, Taichung, Taiwan and Katsuzo and Kiyo Aoshima Memorial Funds, Japan. No competing interest existed. TRIAL REGISTRATION NUMBER: N/A.