Childhood trauma: Unfolding the lifelong impact on mental health

This thesis aimed to understand how childhood trauma (CT), conceptualized as emotional/physical/sexual abuse or emotional/physical neglect before the age of 18 years, shapes mental health, what the potential underlying mechanisms of CT are, and what can be done about it in the context of adult depressive and/or anxiety disorders. The exploration of cross-sectional, longitudinal, and ecological momentary assessment (EMA) data from the Netherlands Study of Depression and Anxiety (NESDA), as well as a meta-analytic combination of results from multiple (inter)national clinical trials on depression treatment was used to examine the impact of CT on psychopathology, explore potential CT mechanisms that may heighten vulnerability for psychopathology, and investigate the impact of CT in the clinical setting.

Our findings indicated that CT is associated with increased severity of various symptoms, including total depressive, anxiety, worry, and fear/phobic, suggesting a broad and nonspecific impact on psychopathology. Moreover, symptom severity persisted over the years, indicating increased chronicity. Our results also revealed that individuals with CT show alterations in the brain, mind, and body, including maladaptive personality characteristics and cognitions, accelerated biological aging, somatic health decline, brain structural and functional changes, greater alterations in daily affect intensity, dysregulated biological stress systems (particularly innate immune system capacity), and engagement in unhealthier lifestyle behaviors. The adverse effects were most pronounced in severe CT cases, characterized by multiple types or higher frequencies of trauma, with minimal differences between CT types. In the clinical setting, depressed adults with CT experienced significant symptom improvement following first-line pharmacological and psychotherapeutic treatments, but were more severely depressed before and after treatment. Hence, our results suggest that CT constitutes a risk factor for various depressive and anxiety symptomatology with multiple potential explanatory pathways.

Prospective longitudinal studies with an integrative approach combining various data sources are essential to understand the complexity behind the enduring impact of CT. CT assessment should be integrated into clinical practice to identify individuals at risk for poor mental and somatic health outcomes. Although existing treatments may benefit patients with CT in reducing depressive symptomatology, the persistently increased severity of symptoms warrants further attention for additional interventions. The most favorable outcomes could be achieved by implementing a holistic approach that incorporates first-line pharmacological and psychotherapeutic treatments with lifestyle modifications, trauma-focused therapies, or stress management interventions, among other treatment modalities. Increased attention should be given to preventative CT strategies that have the potential to break the cycle of intergenerational trauma and offer greater effectiveness and cost-efficiency than addressing a broad spectrum of CT-related mental and somatic health issues later in life.