ABSTRACT
BACKGROUND: Posttraumatic stress disorder (PTSD) in response to psychosis and associated experiences (psychosis-related PTSD, or PR-PTSD) is the subject of a growing field of research. However, a wide range of PR-PTSD prevalence rates has been reported. This may be due to definitional and methodological inconsistencies in the assessment of PR-PTSD. OBJECTIVE: The focus of the review is two-fold. (1) To identify factors that enhance, or detract from, the robustness of PR-PTSD assessment and (2) to critically evaluate the evidence in relation to these identified criteria, including the impact on PR-PTSD prevalence rates. METHOD: Four quality criteria, whose development was informed by mainstream PTSD research, were selected to evaluate findings on PR-PTSD prevalence. Two criteria related to assessment of psychosis-related stressors (participant identification of worst moments of discrete threat events; psychometrically robust trauma measure) and two focussed on PR-PTSD symptom measurement (adequate time elapsed since trauma; use of validated PTSD interview) in the context of psychosis. RESULTS: Twenty-one studies of PR-PTSD, with prevalence rates ranging from 11 to 51%, were evaluated. Fourteen studies (67%) used robust PTSD measures but PR-trauma was not specifically defined or assessed with validated measures. Eleven studies (52%) assessed PTSD before sufficient time had elapsed since the trauma. Due to significant methodological limitations, it was not possible to review PR-PTSD rates and provide a revised estimate of prevalence. CONCLUSIONS: Methodological limitations are common in existing studies of PR-PTSD prevalence. Specific recommendations for improving assessment of psychosis-related trauma are made to guide the development of this new and emerging field. The review concludes with a proposed conceptualisation of PR-PTSD in the context of current diagnostic systems. The utility of the PR-PTSD term and its theoretical underpinnings are discussed.
ABSTRACT
BACKGROUND: Traditional instruments that measure self-esteem may not relate directly to the schema construct as outlined in recent cognitive models. The Brief Core Schema Scales (BCSS) aim to provide a theoretically coherent self-report assessment of schemata concerning self and others in psychosis. The scales assess four dimensions of self and other evaluation: negative-self, positive-self, negative-other, positive-other. METHOD: We analysed the psychometric properties of the BCSS using a sample of 754 students recruited by email and 252 people with psychosis recruited as part of a trial of cognitive therapy. We report the internal consistency, stability and the factor structure of the scale, and the association of the BCSS with measures of self-esteem and with symptoms of paranoia and grandiosity. RESULTS: The BCSS have good psychometric properties and have more independence from mood than the Rosenberg Self-Esteem Schedule. People with chronic psychosis reported extreme negative evaluations of both self and others on these scales, but their levels of self-esteem and positive evaluations of self and others were similar to the student sample. CONCLUSIONS: Extreme negative evaluations of self and others appear to be characteristic of the appraisals of people with chronic psychosis, and are associated with symptoms of grandiosity and paranoia in the non-clinical population. The BCSS may provide a more useful measure of schemata about self and others than traditional measures of self-esteem.
