The primary focus of this dissertation was to increase the knowledge about possible biological factors and psychopathological mechanisms (including HPA-axis functioning, one-carbon and fatty-acid metabolism), as well as some gene-environment interactions for the course of recurrent MDD (MDD-R). Studying MDD-R is important because there are indications that it represents a more biological and genetic determined MDD-subtype, which may be specifically linked to recurrence and CVD-risk.

Research consistently shows that incarcerated juveniles and adults experience high levels of prior traumatic experiences and stressful life events. Yet there is a gap in the literature addressing incarcerated older adults' life-course experiences of traumatic and stressful life events and their initial and current subjective interpretations of these events. Given that untreated trauma has been linked to decreased health and mental well-being, and recidivism, the current study attempts to address this gap.

Psychiatric illnesses are under polygenic influence and are associated with interactions between genetic variants and environmental exposures.1 Gene–environment interactions might not only predict onset of disease, but genetic biomarkers might also help the clinician to select the optimal treatment for patients.2 However, there is a lack of studies on therapygenetics for psychological treatment of psychiatric diseases.

There has been abundant research targeting the secondary and tertiary prevention and treatment of posttraumatic stress disorder (PTSD), including different forms of debriefing, treatments for acute stress disorder, and targeted intervention strategies (M. T. Feldner, C. M. Monson, & M. J. Friedman, 2007). However, there remains a scarcity of research pertaining to the primary, pretrauma prevention of PTSD. A systematic review was conducted in order to identify and synthesize all programs aimed at the primary prevention of PTSD to date.