Psychotic like experiences as part of a continuum of psychosis: Associations with effort-based decision-making and reward responsivity

Research examining psychotic disorders typically involves comparison between individuals with a clinical disorder and healthy controls. However, research suggests that psychotic symptoms, such as delusions and hallucinations, may exist on a continuum ranging from variation in healthy individuals to diagnosable psychotic disorders. On this continuum, some individuals endorse occasional psychotic like experiences (PLEs) that do not cause sufficient impairment or distress to warrant a clinical diagnosis. Given this continuum model, one might expect to observe impairments in those with PLEs in the same behavioral domains impaired in schizophrenia. Thus, we examined two domains typically impaired in schizophrenia, effort allocation and reward responsivity, in a large university sample (n = 126). Participants completed tasks assessing effort-based decision-making, reward responsivity, and questionnaires assessing PLEs. Greater PLEs were associated with greater effort expenditure regardless of probability of receiving a reward or reward value. Higher PLEs were related to greater positive feelings when receiving rewards. Importantly, these relationships remained the same when controlling for other symptoms such as depression, anhedonia, and anxiety. These findings suggest that PLEs may be associated with hypersensitivity to reward at the less severe end of the psychotic continuum, with effort to attain a reward expended in a potentially inefficient manner. This pattern is consistent with models of hyperdopaminergic states in psychotic individuals not taking antipsychotic medications, given the role of dopamine in modulating effort allocation and reward anticipation.