Associations between sex hormones, sleep problems and depression 239 The prospective long-term studies had multiple measurements over time, with multiple momentary cross-sectional assessments of sex hormones, sleep and/or mood. Although the analyses of these studies did assess correlations between sex hormones, sleep problems and mood at each measurement session, their analyses could determine whether sex hormone changes over time make individuals more vulnerable for sleep problems or depression. Thus, lack of longitudinal data analyses limited the scope of these studies. Lee et al., (2000) was the only study that assessed the association between sleep, mood and sex hormones. They found that participant’s negative mood did not correlate with sleep variables in the follicular phase, but in the luteal phase participants with a higher increase in REM sleep latency (which is also seen in depressed patients) reported worse mood scores. The finding that the association between negative mood and REM sleep latency was only seen in the luteal phase might suggest that women are more vulnerable to depression or depressive moods during the luteal phase, even if they do not necessarily suffer from PMDD. This study also found that participants with high progesterone levels showed an mood, in contradiction to other studies that found that higher progesterone levels had a negative effect on mood. However, this could be related to a bias in the study design. Their participants were all women who wanted to conceive, but 12 out of 34 did not experience an ovulation in the month of testing. Ovulation was determined by the researchers through luteal progesterone levels (with high levels of progesterone indicating ovulation), but it is not described in the study whether participants themselves knew whether they had ovulated. It is possible that the lack of ovulation may have affected the anovulatory women’s mood negatively, since the differences in mood scores may also be affected by their disappointment in lack of ovulation that cycle. Only one study (Kische et al., 2016) included male participants in their setup. In men, the effect of endogenous changes in sex hormones are harder to study, since they have no defined moments where their sex hormones endogenously fluctuate (e.g. menstrual cycles). Although the association between testosterone and sleep has been investigated (Leproult & Van Cauter, 2011; Schmid et al., 2012; Wittert, 2014), studies on the relationship
RkJQdWJsaXNoZXIy MTk4NDMw