Exploring the association between social behaviour, trust, and its neural correlates in first episode psychosis patients and in individuals at clinical high risk for psychosis.

Objectives: Psychosis is characterized by paranoid delusions, social withdrawal, and distrust towards others. Trust is essential for successful social interactions. It remains unknown which aspects of social functioning are associated with reduced trust in psychosis. Therefore, we investigated the association between social behaviour, trust, and its neural correlates in a group of individuals with psychotic symptoms (PS‐group), consisting of first episode psychosis patients combined with individuals at clinical high risk. Methods: We compared 24 PS individuals and 25 healthy controls. Affect and social withdrawal were assessed using the Experience Sampling Method. Trust was measured during functional magnetic resonance imaging (fMRI) scanning, using a trust game with a cooperative and unfair counterpart. Results: The PS‐group showed lower baseline trust compared to controls and reported less positive and more negative general affect. Social withdrawal did not differ between the groups. Social withdrawal and social reactivity in affect (i.e., changes in affect when with others compared to when alone) were not associated with trust. On the neural level, in controls but not in the PS‐group, social withdrawal was associated with caudate activation during interactions with an unfair partner. An increase in positive social reactivity, was associated with reduced insula activation in the whole sample. Conclusions: Social withdrawal and social reactivity were not associated with reduced initial trust in the PS‐group. Like controls, the PS‐group showed a positive response in affect when with others, suggesting a decrease in emotional distress. Supporting patients to keep engaging in social interactions, may alleviate their emotional distress. Practitioner points: Individuals with psychotic symptoms show reduced initial trust towards unknown others.Trust in others is not associated with social withdrawal and reported affect when with others, nor when alone.Like controls, individuals with psychotic symptoms showed reduced negative affect and increased positive affect when with others compared to when alone.We emphasize to support individuals with psychotic symptoms to keep engaging in social interactions, given it may reduce social withdrawal and alleviate their emotional distress. [ABSTRACT FROM AUTHOR]