Nocturnal sleep, daytime sleepiness, and napping among women with significant emotional ⁄ behavioral premenstrual symptoms LYNNE J. LAMARCHE 1 , HELEN S. DRIVER 2 , SABRINA WIEBE 1 , LEAH CRAWFORD 1 and JOSEPH M. DE KONINCK 1 1 Sleep Laboratory, School of Psychology, University of Ottawa, Ottawa, ON, 2 Departments of Medicine and Psychology, Kingston General Hospital, QueenÕs University, Kingston, ON, Canada Accepted in revised form 20 June 2007; received 6 February 2007 SUMMARY 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. Setting took place at the sleep laboratory at the University of Ottawa. A total number of participants were 10 women with significant and nine women with minimal emotional ⁄ behavioral premenstrual symptoms (mean age 26 years). The results were compared with the follicular phase, both groups of women had less slow wave sleep and more stage 2 sleep at night, as well as a higher daytime and nocturnal mean and maximum temperature during the late-luteal phase. Women with significant symptoms were sleepier and less alert during the late-luteal phase and had a higher overall mean nocturnal temperature compared with women with minimal symptoms. No significant differences were found between the two groups on nap characteristics and nocturnal sleep characteristics. Results show that women with more severe premenstrual symptoms are sleepier during the late-luteal phase than women with minimal symptoms. The increased daytime sleepiness seems to be unrelated to nocturnal sleep or nap characteristics. keywords daytime sleepiness, napping, nocturnal sleep, premenstrual syndrome INTRODUCTION Sleep difficulty has been reported by up to 42% of healthy middle-aged women (Owens and Matthews, 1998) and com- plaints may be related to different phases of the menstrual cycle. Premenstrual symptoms affect between 10% (Mitchell et al., 1991) and 80% (Hamilton et al., 1984) of menstruating women. Women with severe premenstrual symptoms report sleep-related complaints (Hurt et al., 1992; Mauri et al., 1988) yet few studies have investigated the nature of these sleep disturbances. Studies that have compared sleep during the luteal and follicular phases have conflicting and equivocal findings. On balance, based on retrospective surveys and prospective subjective reports using diaries, women across a wide age range (18–50 years) report more sleep disturbances during the premenstrual week than at other times (Manber and Bootzin, 1997; Patkai et al., 1974), such as increased sleep onset latency (SOL) and number of awakenings (Manber and Bootzin, 1997) and decreased sleep efficiency (Manber and Bootzin, 1997). While some polysomnographic studies find a decrease in the amount of SWS (Cluydts, 1980; Ito et al., 1995) and an increase in stage 1 sleep (Parry et al., 1999) in the luteal phase compared with the follicular phase, other researchers report that differences in sleep parameters in relation to the phases of the menstrual cycle are minimal (Armitage and Yonkers, 1994; Driver et al., 1996; Lee et al., 1990). The severity of premenstrual symptoms experienced by women may have an adverse impact on their sleep architecture. Correspondence: Joseph De Koninck, Sleep Laboratory, School of Psychology, University of Ottawa, 125 University, Ottawa, ON K1N 6N5, Canada. Tel.: +1 613 562 5800 (ext.) 4315; fax: +1 613 562 5147; e-mail: jdekonin@uottawa.ca J. Sleep Res. (2007) 16, 262–268 262 Ó 2007 European Sleep Research Society