Risk factors for premenstrual dysphoric disorder in a community sample of young women: the role of traumatic events and posttraumatic stress disorder.

BACKGROUND: There is some evidence that the onset and course of premenstrual syndrome is related to stress; however, few studies have explored the role of traumatic events and post-traumatic stress disorder (PTSD) as risk factors for the development of premenstrual dysphoric disorder (PMDD).
METHOD: A community cohort of 1488 women (aged 14-24 years at baseline) were prospectively and longitudinally evaluated up to 3 times over a period of about 42 months from 1995 to 1999. The DSM-IV version of the Munich-Composite International Diagnostic Interview was used to establish PMDD and PTSD diagnostic status; stressful life events and conditions were assessed with the Munich Events List and the Daily Hassles Scale. Prevalence and incidence of either threshold or subthreshold PMDD from baseline to the second follow-up were calculated. Risk factors, including prior comorbid mental disorders and traumatic events, were examined using logistic regression analysis.
RESULTS: The incidence of threshold PMDD was 3.0%. The most powerful predictors were subthreshold PMDD at baseline (OR = 11.0, 95% CI = 4.7 to 25.9). Traumatic events greatly increased the odds of developing PMDD at follow-up (OR = 4.2, 95% CI = 1.2 to 12.0). Other predictors were a history of anxiety disorder (OR = 2.5, 95% CI = 1.1 to 5.5) and elevated daily hassles scores (OR = 1.6, 95% CI = 1.1 to 2.3). Both were also associated with the risk of developing subthreshold PMDD, although the association was less robust.
CONCLUSIONS: Traumatic events and pre-existing anxiety disorders are risk factors for the development of PMDD. The underlying mechanisms are unknown, making further investigation necessary.