Clinical trials

During and after pregnancy, a woman's body and brain undergo significant changes that help her adapt to caregiving and emotional needs. However, this period also makes women more susceptible to emotional disorders, such as peripartum depression (PPD), which affects about 10-15% of new mothers. PPD can negatively impact both the mother and her baby, disrupting mood, motivation, and mothering abilities. Hormonal changes and poor sleep are some of the risk factors that might worsen these depressive symptoms. Traditionally, sleep studies on PPD have relied on questionnaires and short-term sleep assessments. With the advent of smartwatches and digital devices, we can now monitor sleep in a home environment over longer periods. Oxytocin, a hormone crucial for childbirth, breastfeeding, and bonding with the baby, is thought to play a role in PPD. Studies suggest that higher levels of oxytocin might be linked to lower levels of postpartum depression, though findings are not always consistent. Oxytocin also affects sleep and is connected to brain areas that regulate reward and motivation. This study aims to explore the relationship between sleep, oxytocin, and reward processing in new mothers. The investigators will include women with varying levels of depressive symptoms and use home-based sleep assessments to gather data. Our goal is to better understand how these factors interact in the postpartum period and how they might influence a mother's mental health and caregiving abilities. The investigators expect that oxytocin levels are reduced in women with higher depressive symptoms and that these reductions are associated with sleep impairments, breastfeeding and altered reward processing.

Pubertal transition leads to enduring neuroendocrine changes along with changes in the epigenome. The prevalence of psychiatric disorders significantly increases in females compared to males after puberty. There is likely to be an interaction between epigenetics, hormones and neurophysiological processes during puberty, leading to the increased prevalence of mental disorders in females. This study aims to shed light on these interactions underlying the emerging sex differences after puberty. Specifically, it seeks to investigate the epigenetic modifications and subsequent changes in gene expression during the pubertal transition and their association with negative emotionality (e.g., acute stress response and depressive symptoms) at molecular, neuronal, subjective and physiological levels.

Oxytocin is a hypothalamic neuropeptide that is best known for its peripheral physiological effects in the female organism i.e., uterine contractions during birth. The neuropeptide furthermore affects reward processing and metabolic functions such as eating behavior and body weight. Oxytocin receptors are present in brain regions associated with the processing of rewards, e.g., ventral tegmental area (VTA), nucleus accumbens (NAcc) and nucleus stria terminalis. Previous studies indicate that oxytocin interacts with sex hormones such as estradiol in a sex-specific manner. Despite known sex differences in oxytocin function, most studies i.e., on the metabolic effects of oxytocin in humans have so far focused on young, healthy men. Intranasal oxytocin administration has emerged as a method to experimentally investigate central nervous effects of oxytocin in the absence of relevant side effects. In the proposed study the investigators aim to systematically investigate the acute effect of intranasal oxytocin on reward processing in relation to circulating and synthetic sex hormones in healthy, naturally cycling women and in women taking hormonal oral contraceptive pills. The investigators will administer 24 international units (IU) of intranasal oxytocin vs. placebo and investigate neural correlates in a 3T MRI scanner including functional imaging during a reward processing task, changes in brain anatomy and connectivity. Additionally, metabolic functions, eating behavior and changes in mood and wellbeing will be assessed and blood will be drawn to assess parameters of hormonal and metabolic status.