Social defeat and psychosis-related outcomes: Associative and experimental tests related to the nature of defeat, specificity of outcomes, and psychosis-proneness

Several forms of social defeat, including ostracism, discrimination, bullying, and related experiences, have been associated with psychotic disorders and experiences. The social defeat hypothesis of schizophrenia attempts to explain these associations by positing that chronic exclusion due to having outsider status leads to deleterious neurobiological changes that produce psychosis. Here, we test non-neurobiological tenets of this theory, including the relative impact of daily, real-world, chronic social defeat versus an acute, time-limited, experimentally-induced socially defeating experience (social exclusion), the moderating role of psychosis-proneness, and the specificity of social defeat on psychosis-related outcomes. We find that real-world, chronic, but not acute, time-limited, laboratory-based social defeat is associated with decreased trust, but not false-alarms on an auditory signal detection task. These associations were qualified by interactions that are in line with social reconnection (i.e., positive appraisals of social stimuli following exclusion). Real-world, chronic social defeat was also associated with delusion- and hallucination-proneness. Together, these data highlight the importance of daily, real-world forms of social defeat versus laboratory manipulations on specific psychosis-related outcomes.