Traumatic life event exposure and attenuated psychosis: Symptom specificity and explanatory mechanisms

Abstract

Although genetic factors appear to contribute substantially to the onset of psychotic disorders, environmental factors also influence the development and course of psychosis. One environmental risk factor that has been robustly associated with multiple psychosis outcomes is exposure to traumatic life events (TLEs). Specifically, TLEs have been associated with increased risk of psychotic disorders, with the prodrome of psychosis, and with dimensional measures of psychotic symptoms, such as attenuated positive psychotic symptoms. Nevertheless, TLEs have been linked to various mental disorders; therefore, the specificity of TLEs to psychosis remains unclear. Similarly, the mechanisms underlying the TLE-psychosis relation have not been fully delineated. The current project addressed these gaps by exploring three areas within the field of TLEs and psychosis. The first is by reviewing the literature on two understudied areas of the trauma and psychosis literature: 1) the specificity between trauma and psychosis in relation to other disorders that often result post-trauma, and 2) proposed mechanisms that uniquely link trauma to psychosis. Second, this project tested whether attentional biases, present in samples with trauma histories and experiencing attenuated forms of psychosis, were similar within both populations. Third, this project examined multiple putative mechanisms influencing the association between TLEs and attenuated psychosis that have been proposed, but not fully tested, in psychosis research, including dissociation, negative self-schemas, negative other-schemas, external locus of control, and stress sensitivity. Analysis of variance suggested that individuals with TLE histories demonstrate attentional biases for physical abuse words and overall TLE-related words, but that experiencing attenuated positive psychotic symptoms does not increase attentional biases in conjunction with a TLE history. Additionally, a bootstrapping method for examining multiple mediation indicated that increases in dissociation, negative self- and other-schemas, external locus of control, and perceived stress mediate the relationship between TLEs and attenuated psychosis. Collectively, this project underscores the importance of targeting multiple cognitive-based mechanisms that may emerge post-trauma in order to reduce psychotic-like experiences or disorders.