|PhD ceremony:||M.W. Masselink, MSc|
|When:||December 04, 2019|
|Supervisor:||prof. dr. A.J. (Tineke) Oldehinkel|
|Co-supervisor:||dr. G.H. van Roekel|
|Where:||Academy building RUG|
|Faculty:||Medical Sciences / UMCG|
In this dissertation, I investigated the associations between self-esteem and depressive symptoms among adolescents and young adults. More specifically, I investigated whether a motivation to avoid potentially threatening situations, the motivation to approach potentially rewarding situations and social factors (i.e. social contact, social problems, and social support), are part of the mechanism underlying the associations between self-esteem and depressive symptoms. I have investigated this mechanism across different time scales, ranging from multiple years between measurement moments, to only a couple of hours, in order to look at the associations during daily life. The results showed that low self-esteem during early adolescence was a vulnerability for developing depressive symptoms during late adolescence and early adulthood. However, the effect was small, meaning that having a low self-esteem does not necessarily predispose young adolescents to develop depressive symptoms. Low self-esteem was also associated with avoidance motivation and social problems, which both were associated with depressive symptoms. Looking at associations during the day, I found that low self-esteem was associated with avoidance, less time spent on social interactions, and sadness, when measured at the same time point. I was not able to find evidence that these variables were meaningfully associated over time. Another important focus of my dissertation was on methodological advancements and improving the scientific process with the incorporation of Open Science principles into research. Open Science principles are aimed at increasing reliability, transparency, reproducibility and replicability of research.