Figure 3. Mean + SEM polysomnography measures as a function of age category. P-values denote Bonferroni-adjusted significance of differences from menopausal mean. In confirmation of the RS analyses, we found only one significant effect of diagnosis in relation to the age category: REM percentage was significantly greater in DP vs NC across age groups (Group means + SEM =22.3+0.8% vs 19.6+0.8%, F(1,130) = 7.190, P=.008). Post-hoc analyses showed that DP who were 37 years of age or older had significantly greater REM percentage than NC Inhibitors,research,lifescience,medical (F(1,134) =9.285, P=.003); DP younger than 37 years old did not

differ significantly from NC (P> .05). Discussion We evaluated objectively measured PSG sleep cross-sectionally in women, examining the combined effects of mood, reproductive status, and age on sleep parameters. Given the unique challenges to sleep that women may face during periods of reproductive change, we Inhibitors,research,lifescience,medical sought to elucidate the contribution of these changes to sleep alteration, beyond those accounted for by the aging process alone. In the first level of our analyses we examined the contribution of depressed mood on PSG. Contrary to expectation, we found a reliable effect of depressed mood on only one PSG measure: REM percentage, which was significantly elevated in DP versus NC across both RS and age. These results are consistent with earlier

evidence showing increased REM percentage as a characteristic marker of sleep in depressed individuals Inhibitors,research,lifescience,medical (eg, Frank et al,39 Walker60) and a decrease from baseline in REM percentage in depressed patients during recovery.61 With this exception of REM percentage, the

absence of reliable changes in objective sleep measures in depressed Inhibitors,research,lifescience,medical women across ages and reproductive epochs confirms earlier findings (see review in ref 20), and raises the question: why are subjective complaints of sleep disturbances in depression not uniformly confirmed by PSG analysis? While our data cannot provide a definitive answer, it is conceivable that measurements made under strictly controlled laboratory conditions lack sufficient ecological validity relative to natural sleep, thereby Inhibitors,research,lifescience,medical leading to systematic see more underestimates of the sleep alterations depressed women experience under natural conditions.29,62,63 Alternatively, subjective reports may actually provide an accurate representation of a patient’s sleep, but procedures by which “objective” sleep is measured may fail to identify small EEG differences (ie, microarousals and high-frequency EEG) that may Thymidine kinase contribute to the perception of poor sleep.64,65 Consistent with other reports14 we also observed a trend toward decreased REM percentage across the lifespan which was observed only in the NC but not DP women. Conversely, the lack of difference in other objective PSG sleep measures between the groups appears to be at odds with studies that have found that DP typically exhibit reduced REM latencies, as well as increased SL, and WASO.