Menstrual cycle phase and premenstrual symptoms in relation with the stress response: an fMRI study

Objective: The study aimed to investigate the neural, behavioral, and endocrine stress responses in women with premenstrual syndrome (PMS) compared to those without PMS across different phases of their menstrual cycle.

Methods: The researchers recruited 26 women with PMS and 24 women without PMS, who participated in two functional magnetic resonance imaging (fMRI) sessions during the mid-follicular phase (days 5-11) and late-luteal phase (days -7 to -1) of their menstrual cycle. Participants completed the Montreal Imaging Stress Task (MIST) during the fMRI sessions.

Subjective stress ratings and salivary cortisol levels were collected at six time points before and after stress induction. The researchers analyzed stress-related brain activation using whole-brain and region-of-interest analyses.

Results: The subjective stress ratings increased as expected from before to after the MIST, with no significant differences between the PMS and non-PMS groups or between the follicular and luteal phases. Salivary cortisol levels were significantly higher during the mid-follicular phase, but there were no group or phase differences or significant pre-post MIST differences.

The stress task activated stress-related regions in the brain, but there were no significant effects of group or menstrual cycle phase on the neural stress response. When considering premenstrual symptom severity as a predictor of brain activation, a significant group-by-symptom severity interaction was found in the right inferior frontal gyrus and the right superior temporal gyrus.

Conclusion: The study found that neural responses to psychosocial stress were stable across menstrual cycle phases in both PMS and non-PMS women. However, individual differences in symptom severity may be associated with differences in stress-related brain activation.