Premenstrual mood and empathy after a single light therapy session

Area of Science:

• Psychiatry
• Neuroscience
• Chronobiology

Background:

• Premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) significantly impact women's mood and well-being.
• Light therapy is a recognized treatment for mood disorders, but its effects on cognitive empathy in premenstrual women are not well understood.
• Hormonal contraceptive use may influence responses to light therapy.

Purpose of the Study:

• To investigate if acute changes in cognitive empathy mediate the mood effects of light therapy in premenstrual women.
• To assess the impact of a single light therapy session on mood and cognitive empathy.
• To explore potential moderating effects of hormonal contraceptive use.

Main Methods:

• A participant-blind, between-groups study involving 48 premenstrual women (17 with moderate-to-severe PMS/PMDD).
• Intervention: 30 minutes of bright light therapy (5,000lx, blue-enriched) versus a sham session (200lx).
• Assessments: Mood (Positive Affect and Negative Affect Schedule, Affect Grid) and cognitive empathy (computerized empathic accuracy task) before, immediately after, and 60 minutes post-intervention.

Main Results:

• No significant effect of light therapy on cognitive empathy was observed.
• Bright light exposure significantly reduced negative affect in women not using hormonal contraceptives.
• No mood improvements were noted in women using hormonal contraceptives.

Conclusions:

• A single light therapy session does not appear to alter cognitive empathy in premenstrual women.
• Cognitive empathy may not be a mediator for light therapy's mood effects in this population.
• Bright light therapy shows potential for improving mood in premenstrual women, particularly those not using hormonal contraceptives.