The effects of developmental trauma on reinforcement learning and its relationship to psychotic experiences: a behavioural study

BackgroundDevelopmental psychological trauma can impact several key neurocognitive domains, including reward processing, and is associated with increased risk of psychosis in adulthood. Aberrant reinforcement learning (RL), an important component of reward processing, has been implicated in the pathophysiology of psychosis by altering information processing through changes in hierarchical predictive coding. We therefore sought to investigate RL in survivors of developmental trauma and its relationship to psychotic experiences. MethodsWe recruited two groups of adults, one with self-reported exposure to multiple forms of developmental trauma (n=115), and a control group without any known history of maltreatment (n=85). Participants completed measures of psychotic experiences (Community Assessment of Psychic Experiences) and undertook a probabilistic selection task designed to assess RL from positive versus negative outcomes. We analysed group differences for main effects and investigated relationships between developmental trauma, RL and psychotic experiences using regression modelling and mediation analysis. ResultsDevelopmental trauma was associated with psychotic experiences (adjusted R2=0.41, p=0.004) and impaired RL (Fdf=6.291,89, p=0.014). Impaired RL mediated the association between developmental trauma and psychotic experiences (indirect effect {beta} = 0.60, 95% CI, 0.01-1.36). ConclusionsOur findings implicate aberrant RL as a possible mechanism through which developmental trauma may increase risk of psychosis. Further research is therefore warranted to understand the specific processes that characterise these putative trauma-induced vulnerability mechanisms and how they may contribute to the development of psychopathology.