Abstract
OBJECTIVE: Treatment in the ultra-high risk stage for a psychotic episode is critical to the course of symptoms. Markers for the development of psychosis have been studied, to optimize the detection of people at risk of psychosis. One possible marker for the transition to psychosis is social cognition. To estimate effect sizes for social cognition based on a quantitative integration of the published evidence, we conducted a meta-analysis of social cognitive performance in people at ultra high risk (UHR). METHODS: A literature search (1970-July 2015) was performed in PubMed, PsychINFO, Medline, Embase, and ISI Web of Science, using the search terms 'social cognition', 'theory of mind', 'emotion recognition', 'attributional style', 'social knowledge', 'social perception', 'empathy', 'at risk mental state', 'clinical high risk', 'psychosis prodrome', and 'ultra high risk'. The pooled effect size (Cohen's D) and the effect sizes for each domain of social cognition were calculated. A random effects model with 95% confidence intervals was used. RESULTS: Seventeen studies were included in the analysis. The overall significant effect was of medium magnitude (d = 0.52, 95% Cl = 0.38-0.65). No moderator effects were found for age, gender and sample size. Sub-analyses demonstrated that individuals in the UHR phase show significant moderate deficits in affect recognition and affect discrimination in faces as well as in voices and in verbal Theory of Mind (TOM). Due to an insufficient amount of studies, we did not calculate an effect size for attributional bias and social perception/ knowledge. A majority of studies did not find a correlation between social cognition deficits and transition to psychosis, which may suggest that social cognition in general is not a useful marker for the development of psychosis. However some studies suggest the possible predictive value of verbal TOM and the recognition of specific emotions in faces for the transition into psychosis. More research is needed on these subjects. CONCLUSION: The published literature indicates consistent general impairments in social cognition in people in the UHR phase, but only very specific impairments seem to predict transition to psychosis.