Menstrual cycle phase modulates emotional conflict processing in women with and without premenstrual syndrome (PMS)--a pilot study

Abstract

Background: Premenstrual syndrome (PMS) is characterized by a cluster of psychological and somatic symptoms during the late luteal phase of the menstrual cycle that disappear after the onset of menses. Behavioral differences in emotional and cognitive processing have been reported in women with PMS, and it is of particular interest whether PMS affects the parallel execution of emotional and cognitive processing. Related to this is the question of how the performance of women with PMS relates to stress levels compared to women without PMS. Cortisol has been shown to affect emotional processing in general and it has also been shown that women with severe PMS have a particular cortisol profile.

Methods: We measured performance in an emotional conflict task and stress levels in women with PMS (n = 15) and women without PMS (n = 15) throughout their menstrual cycle.

Results: We found a significant increase (p = 0.001) in the mean reaction time for resolving emotional conflict from the follicular to the luteal cycle phase in all subjects. Only women with PMS demonstrated an increase in physiological and subjective stress measures during the luteal menstrual cycle phase.

Conclusions: Our findings suggest that the menstrual cycle modulates the integration of emotional and cognitive processing in all women. Preliminary data are supportive of the secondary hypothesis that stress levels are mediated by the menstrual cycle phase only in women with PMS. The presented evidence for menstrual cycle-specific differences in integrating emotional and cognitive information highlights the importance of controlling for menstrual cycle phase in studies that aim to elucidate the interplay of emotion and cognition.

Figure 1. Affective symptoms in PMS subjects and control subjects across the menstrual cycle.

Top Panel: Beck Depression Inventory (BDI) scores in women with premenstrual syndrome (PMS) are significantly increased (*: p = 0.025) in the luteal cycle phase (dark grey) compared to the follicular phase (light grey) but not in women without PMS (CTL). Bars represent one standard deviation. Bottom Panel: Hamilton Depression Scale (HAM-D) scores are significantly increased in women with PMS (*: p = 0.001) in the luteal cycle phase (dark grey) compared to the follicular phase (light grey) but not in women without PMS (CTL). Bars represent one standard deviation.

Figure 2. Resolution of Emotion Conflict differs according to menstrual cycle phase.

Top panel: Scatter plots show individual differences in reaction time (sec) between the incongruent and congruent condition of the emotional Stroop task in the follicular and the luteal cycle phase in all subjects (mean reaction time shown in black). These data indicate a significant increase (p = 0.001) in mean reaction time for resolving emotional conflict between the follicular and the luteal cycle phase in all subjects. Bottom panel: Boxplots-bars show mean differences in reaction time (sec) between the incongruent and congruent condition of the emotional Stroop task in the follicular and the luteal cycle phase split by subject group (dark grey  =  PMS group, light grey  =  control group). Whiskers represent minimum and maximum of data-range. On average, the PMS group tended to show a faster mean reaction time compared to the control group (follicular phase: PMS group mean ± SD  = 0.02±0.02 sec, Control group mean ± SD  = 0.03±0.02 sec; luteal phase: PMS group mean ± SD  = 0.04±0.03 sec, Control group mean ± SD  = 0.05±0.03 sec), however, overlap exists and this difference is not significant (follicular phase: p = 0.17; luteal phase: p = 0.19).

Figure 3. Heightened physiological and subjective stress levels in women with premenstrual syndrome (PMS) in the luteal menstrual phase.

Top Panel: Boxplots-bars show mean salivary cortisol values (ln) comparing the follicular and the luteal cycle phase in PMS subjects (dark grey) versus control subjects (light grey). Whiskers represent minimum and maximum of data-range. On average, salivary cortisol levels increased from the follicular to the luteal cycle phase in the PMS group (p = 0.04). Bottom panel: In the Perceived Stress Scale (PSS), the PMS group (dark grey) displayed a similar trend for an increase from the follicular to the luteal cycle phase (p = 0.20) as depicted by boxplot-bars. On average, the PMS group (dark grey) tended to report higher subjective acute stress reactivity compared to the control group (light grey), revealing a significant difference for the luteal cycle phase (p = 0.01). Whiskers represent minimum and maximum of data-range.