Kiezen voor duisternis wanneer er licht wordt aangeboden: Het doorgronden van hardnekkige negatieve zelfgerichte gedachten bij adolescenten met depressie

Adolescence is a critical developmental period marked by increased vulnerability to depression, coinciding with a phase of intense self-discovery. During this time, individuals are particularly susceptible to persistent negative self-referential thinking, which has been identified as a potential risk factor for the development of depressive symptoms. At the start of my PhD, a novel paradigm, the Emotional Reversal Learning Task (ERLT), was developed to assess such thinking patterns. Previous research in adults, using the ERLT, demonstrated a link between persistent negative self-referential thinking and depressive symptoms. However, its predictive value for future depressive symptoms in adolescents, and its potential as a risk factor to target in early intervention, remained unclear. To address this gap, the first part of the dissertation (Chapters 2, 3 and 4) investigates the potential role of persistent negative self-referential thinking as a risk factor for depressive symptoms in adolescence. These chapters examine the association both cross-sectionally and longitudinally. The findings offer inconsistent evidence for a cross-sectional association between persistent negative self-referential thinking and depressive symptoms, and no evidence was found for a longitudinal effect. To further enhance our understanding of the interplay between multiple risk factors for adolescent depression, the dissertation also examines the relation between persistent negative self-referential thinking and two additional key factors: temperament and emotion regulation. Chapters 3 and 4 test two risk models for depressive symptomatology: (1) whether temperament underlies persistent negative self-referential thinking; and (2) whether emotion regulation mediates the relation between such negative thinking patterns and depressive symptoms. Neither model was supported by the data in Chapter 3 or Chapter 4. The final empirical chapter (Chapter 5) explores a potential intervention aimed at reducing persistent negative self-referential thinking. Specifically, positive memory specificity training, grounded in the principles of cognitive bias modification, was used to enhance access to positive memories. This intervention is intended to help adolescents disengage from negative self-referential thoughts. Preliminary evidence from Chapter 5 suggests that the training may have a beneficial effect in reducing these thinking patterns. Finally, the general discussion synthesizes the findings from all chapters, highlighting the most important findings of the dissertation and discussing their implications for future research and clinical practice.