Posttraumatic Stress Disorder and Likelihood of Hormone Therapy Use among Women in the Nurses' Health Study II: A 26-Year Prospective Analysis

Background: Posttraumatic stress disorder (PTSD) is associated with higher risk of certain chronic diseases, including ovarian cancer, but underlying mechanisms remain unclear. Although prior work has linked menopausal hormone therapy (MHT) use with elevated ovarian cancer risk, little research considers PTSD to likelihood of MHT use. We examined whether PTSD was prospectively associated with greater likelihood of initiating MHT use over 26 years.

Methods: Using data from the Nurses' Health Study II, with trauma and PTSD (symptoms and onset date) assessed by screener in 2008 and MHT assessed via biennial survey (from 1989), we performed Cox proportional regression models with women contributing person-years from age 36 years. Relevant covariates were assessed at biennial surveys. We considered potential effect modification by race/ethnicity, age at baseline, and period (1989–2002 vs. 2003–2015).

Results: Over follow-up, 22,352 of 43,025 women reported initiating MHT use. For example, compared with women with no trauma, the HR for initiating MHT was 1.18 for those with trauma/1–3 PTSD symptoms [95% confidence interval (CI), 1.13–1.22] and 1.31 for those with trauma/4–7 PTSD symptoms (95% CI, 1.25–1.36; P trend < 0.001), adjusting for sociodemographic factors. Associations were maintained when adjusting for reproductive factors and health conditions. We found evidence of effect modification by age at baseline.

Conclusions: Trauma and number of PTSD symptoms were associated with greater likelihood of initiating MHT use in a dose–response manner.

Impact: MHT may be a pathway linking PTSD to altered chronic disease risk. It is important to understand why women with PTSD initiate MHT use.