Nocturnal sleep, daytime sleepiness, and napping among women with significant emotional/behavioral premenstrual symptoms.

The objective of this study is to examine daytime sleepiness and alertness and nap characteristics among women with significant emotional/behavioral premenstrual symptoms, and to determine their relationship with nocturnal sleep. Participants spent one night during the follicular phase and two nights during the late-luteal phase, one of which occurred after a 40 min opportunity to nap, sleeping in the laboratory. Subjective measures of sleepiness and alertness were completed during the afternoon of each recording.