Person-environmental interactions in psychosis

This thesis’ first aim was to evaluate various potential pathways to development- and course of psychotic symptoms and disorders. The data used concerned part of the Dutch national Genetic Risk and Outcome of Psychosis (GROUP) study. In particular research questions addressed processes related to the ‘vulnerability-stress model’. This thesis found further support for interactions between certain environmental risk factors and vulnerability factors for psychosis. Vulnerability factors studied included familial risk for psychosis, impaired social cognition, insecure attachment styles, certain personality traits and subjective well-being. Environmental risk factors studied were childhood trauma and adult life events. Its second aim was to evaluate effectiveness of cognitive behavioural approaches to psychosis. The effectiveness of metacognitive therapy was compared with occupational therapy in people with a recent-onset psychotic disorder. Findings suggest favorable effects of metacognitive training on paranoid reactivity compared to occupational therapy. Also, a CBT approach focusing on social activation (CBTsa) showed promising results in decreasing social withdrawal in early psychosis patients compared to TAU.