General introduction 25 3.4. Gender-affirming hormones and sleep Studies on GAHT and sleep are very scarce. Although the prevalence of poor sleep in transgender persons was estimated to be 80% (Auer et al., 2017), the effect of GAHT on insomnia, sleep quality or chronotype has not yet been studied. One study investigated the effects of three months of GAHT on sleep EEG outcomes, but they only examined effects of feminizing GAHT in seven transgender women (Kunzel et al., 2011). The authors found an increase in light sleep, and no other changes in sleep EEG in participants. The small study sample size and lack of participants using masculinizing GAHT largely limited the generalizability of this study. 4. This thesis Aims This thesis adds to the current literature by focusing on research gaps (as described in Box 1.1) in the relation between sex hormones, sleep and depression. We focused on three specific research aims. First, we aimed to examine the effects of OC use and GAHT use on depression, including depression subtypes and symptomatology. Second, we aimed to examine the effects of OC use and GAHT use have on subjective sleep, sleep architecture and chronotype. Third, we aimed to examine the effects of sex hormones on the association between depression and sleep. Hypotheses We hypothesized that the use of OCs would result in changes in depression and sleep in line with findings in sex hormone intervention studies, and that the use of GAHT would results in changes in depression or sleep in line with the cisgender sex differences in the population. We firstly hypothesized that use of female hormones, including OC and feminizing GAHT, would be associated with increases in depressive symptoms and specifically with increased atypical depression symptoms. Vice versa, we hypothesized that masculinizing hormone use would be associated with reduced depressive symptoms and specifically with reduced symptoms of atypical depression.
RkJQdWJsaXNoZXIy MTk4NDMw