Premenstrual dysphoric disorder and changes in frontal alpha asymmetry

Objective: Since the clinical picture of premenstrual dysphoric disorder (PMDD) in the Luteal phase of the menstrual cycle is characterized by extreme negative affect, we predicted and obtained a change in frontal cortical EEG alpha asymmetry, which has been shown to be an index of affect. Method: We observed two monthly cycles for five women diagnosed as having PMDD and one monthly cycle for five non-PMDD control subjects. Results: Asymmetry percent scores for the five PMDD women, and for the five control subjects before and after the Luteal phase were typically within the normal non-depressed range, however the asymmetry scores for the PMDD group fell into the negative range during the Luteal period while the control subjects remained stable. Discussion: We predicted alpha asymmetry scores would be affected by the luteal phase in PMDD cases. This hypothesis was clearly confirmed.