BACKGROUND: The cognitive model of negative symptoms of schizophrenia suggests that defeatist performance beliefs (DPB), or overgeneralized negative beliefs about one\'s performance, are an intermediary variable along the pathway from impaired neurocognitive performance to negative symptoms and functioning in daily life. Although reliable associations between these variables have been established in chronic schizophrenia, less is known about the nature of these relationships in recent-onset schizophrenia (ROSz). This current study tested the associations between DPB and variables in the cognitive model (neurocognitive performance, negative symptoms, functioning) as well as mediation by DPB of the association between neurocognitive performance and negative symptoms in ROSz.
METHODS: A total of 52 participants (32 adults with ROSz and 20 non-psychiatric healthy comparators; HC) completed in-lab measures of neurocognitive performance, self-reported defeatist performance beliefs, and clinician administered measures of negative symptoms and functional outcome. Bivariate relationships among these variables were tested with Pearson correlations. Bootstrapped regression analyses were conducted to test the strength of the indirect effect of neurocognitive performance on negative symptoms through DPB.
RESULTS: Defeatist performance beliefs were significantly elevated in ROSz, and were associated with neurocognitive performance, negative symptoms, and functional outcome as predicted by the cognitive model. There was a significant indirect effect of neurocognition on experiential negative symptoms through DPB, indicating DPB are a partial mediator of the relationship between neurocognitive performance and negative symptoms.
CONCLUSIONS: These findings are consistent with the cognitive model of negative symptoms and extend previous findings in both ROSz and established schizophrenia. Specifically, these data demonstrate that DPB are elevated among ROSz and the associations with neurocognition and clinical outcomes (e.g., negative symptoms and functioning) are of similar magnitude to those reported in chronic schizophrenia. DPB may therefore be a viable treatment target in the early course of illness.

Negative symptoms of schizophrenia robustly predict functional outcomes but remain relatively resistant to available treatments. Better measures of negative symptoms, especially motivational deficits, are needed to better understand these symptoms and improve treatment development. Recent research shows promise in linking behavioral effort tasks to motivational negative symptoms, reward processing deficits, and defeatist attitudes, but few studies account for individual or group (patient v. control) differences in cognitive ability to perform the tasks. Individuals with poorer abilities might be less motivated to perform tasks because they find them more difficult to perform. This study used a personalized digit span task to control task difficulty while measuring task effort via pupillary responses (greater dilation indicates greater cognitive effort) at varying monetary rewards ($1 & $2). Participants with schizophrenia (N = 34) and healthy controls (N = 41) performed a digit span task with personalized max span lengths and easy (max- 2 digits) and overload (max+ 2 digits) conditions. Consistent with many studies, pupillary responses (cognitive effort) increased with greater difficulty until exceeding capacity. A similar pattern of reward responsivity was seen in both groups, such that greater reward increased dilation (effort) comparably for both groups when difficulty was within capacity. Neither patients nor controls exerted increased effort for greater reward when difficulty exceeded capacity. In patients, positive relationships were found between pupil dilation and defeatist performance beliefs if task difficulty was within capacity; a relationship that reversed if the task was too difficult. The findings demonstrate the importance of accounting for cognitive capacity and task difficulty when evaluating motivation and reward sensitivity and illustrate the utility of pupillary responses as an objective measure of effort in schizophrenia.

Neurocognitive impairment is associated with negative symptoms and poor real world functioning in schizophrenia. Dysfunctional attitudes (e.g., \"If I fail partly, it is as bad as being a complete failure\") have been found to mediate these relationships between neurocognition and negative symptoms and functioning. In this study, these relationships were examined in 179 participants with schizophrenia or schizoaffective disorder using structural equation modeling. Defeatist attitudes were found to mediate the relationship between neurocognition and negative symptoms but not the relationships between neurocognition and performance-based or self-reported functioning. A full model with the best fit showed mediation between neurocognition and self-reported functioning through two different pathways: One from neurocognition to functional skill capacity to real-world functioning, and a second from neurocognition to defeatist attitudes to negative symptoms to real-world functioning. These results may implicate skill deficits and defeatist attitudes as a separate treatment targets for negative symptoms and functioning in schizophrenia.