Stress and rumination in Premenstrual Syndrome (PMS): Identifying stable and menstrual cycle-related differences in PMS symptom severity.

Since the inclusion of Premenstrual Dysphoric Disorder (PMDD) as a mood disorder in the DSM-5, Premenstrual Syndrome (PMS) symptoms have received more attention from researchers and clinicians. In this large-scale study, we investigated core psychological concepts relevant to mood disorder vulnerability between people with 1) no to mild, 2) moderate to severe, and 3) PMDD levels of PMS symptoms. Several trait measures related to mood disorders including depressive symptoms, feelings of stress and anxiety, and ruminative thinking were measured (single measurement, N = 380) along with state (momentary) reports of stress and stress-related perseverative thinking (measured twice, once in the follicular and once in the premenstrual/luteal phase, N = 237). We consistently observed that participants with higher severity of PMS symptoms also scored higher on depression, anxiety, stress, and rumination (trait measures). We also found consistent increases in momentary stress and stress-related perseverative ruminative thinking with increased PMS symptoms at each of our two test moments (in the middle of the follicular and premenstrual/luteal phase respectively). Interestingly, we did not find significant differences between our two test moments for any group, despite PMS being characterized by specific systems in the premenstrual/luteal phase. However, this could be due to noise surrounding the testing moments due to the temporal resolution of the questionnaires and the menstrual cycle estimation method. Nevertheless, these results suggest that stress and rumination are important psychological mechanisms to consider in PMS. Future PMS research studying stress and rumination on a day-to-day basis in combination with hormonal measures is warranted.