The main hormone thought to be involved in PMDs is which?

• A. Estrogen
• B. Testosterone
• C. Progesterone
• D. Cortisol

Answer: (C)

Progesterone is the main hormone thought to be involved in PMDs because the mood symptoms often track with the luteal phase of the cycle, when progesterone rises after ovulation and then falls sharply before menstruation. The brain’s response to progesterone metabolites, especially allopregnanolone, modulates GABA-A receptor activity and can influence anxiety, mood, and irritability. When progesterone levels drop, this neuroactive effect wanes, which can trigger the cyclic mood symptoms seen in PMD/PMDD. Estrogen also fluctuates, but the characteristic mood changes are most closely linked to progesterone withdrawal. Cortisol and testosterone aren’t primary drivers of these premenstrual mood patterns.