General introduction 27 Box 1.2: Study cohorts in this thesis. To investigate the research questions, we used data from different cohorts and study populations. The distribution of the cohorts in the different chapters of this thesis are also described in Table 1.1. Oral contraceptives OC use was studied in data from the Netherlands Study of Depression and Anxiety (NESDA) and in data from the Center for Integrated Molecular Brain Imaging (Cimbi) database. NESDA is a multi-centre longitudinal naturalistic cohort study with 2981 participants, who were followed up for 9 years in five follow-up waves. It aims to describe the longterm course and consequences of depression and anxiety and to study possible biological and psychosocial predictors of depression and anxiety. The NESDA study conducted interviews, questionnaires, medical examinations and collected demographic, psychosocial, clinical and biological data (Penninx et al., 2008). The Cimbi database is a database containing study data from over 2000 healthy volunteers and from patients with psychiatric or somatic illnesses participating in studies conducted within the Lundbeck Foundation Center for Integrated Molecular Brain Imaging (Cimbi) in Copenhagen, Denmark. Study data from neuroimaging and psychiatry studies from 2008 onwards were saved in a structured and standardized manner, in order to enable researchers to conduct secondary analyses on previously collected data. The database currently holds data from over 2000 participants, both healthy volunteers and patients, including neuroimaging data, genetic and biochemical data, questionnaire data and data from neuropsychological tests (Knudsen et al., 2016). Gender-affirming hormone therapy Effects of GAHT were studied in the European Network for the Investigation of Gender Incongruence (ENIGI) study and the Relationship between Emotions and Sleep in Transgender persons: Endocrinology and Depression (RESTED) study. The ENIGI study is a multi-centre observational prospective study, with participating centres from Ghent (Belgium), Oslo (Norway), Florence (Italy), Tel Aviv (Israel) and Amsterdam (the Netherlands). Within the ENIGI study, questionnaires on sleep quality, insomnia and depression were collected at the start of GAHT and after three, six, nine and twelve months of GAHT, depending on the study outcome, and data on comorbidity, medication use, hormone dosage and forms and serum hormone levels were collected from medical patient files (Dekker et al., 2016). The RESTED study is a multi-centre prospective cohort study with the aim of studying the effects of GAHT on sleep and depression, with participating centres from Amsterdam (the Netherlands) and Groningen (the Netherlands). The RESTED study assessed depressive symptom severity, sleep quality and insomnia, sleep EEG and chronotype before starting GAHT, after three months of GAHT and after twelve months of GAHT. These data were combined with data on comorbidity, medication use, hormone dosage and forms and serum hormone levels from medical patient files.
RkJQdWJsaXNoZXIy MTk4NDMw