Childhood maltreatment enhances flexibility in reward learning and blunts prefrontal representation of environmental instability

Childhood maltreatment significantly impacts future mental health, but the mechanisms linking maltreatment and psychopathology remain unclear. Neurocognitive adaptations following maltreatment may constitute a latent vulnerability for mental health problems. While previous research shows that maltreatment alters threat and reward processing, its effects on learning and decision-making are poorly understood. We investigated how childhood maltreatment influences future learning and decision-making motivated by win-seeking vs. loss-avoidance in volatile environments. Adolescents aged 12-17 with (n=59) and without (n=46) maltreatment exposure completed a probabilistic reversal learning task with separate win-seeking and loss-avoidance conditions during fMRI. We employed computational modelling to assess latent learning processes. We explored effects of the extent of maltreatment and psychiatric symptoms. A belief-based Hidden Markov model showed that maltreatment-exposed individuals expected less stable reward contingencies in in the win-seeking condition than controls. Congruently, maltreated adolescents perseverated less and thus outperformed controls after reversals in the win-seeking condition. At the neural level, maltreated adolescents displayed lower right dorsolateral prefrontal cortex activation associated with environmental changes (upcoming reversals). In maltreated adolescents, lower estimates of stability in the win condition were associated with more psychiatric symptoms and impaired performance during stable task phases. Together, our results show that childhood maltreatment may lead to neurocognitive alterations that enhance flexibility in win-seeking contexts, consistent with an adaptive calibration account of maltreatment. These alterations, if excessive, lead to maladaptive decision-making in stable environments and may also contribute to the development of psychiatric symptoms.