Defeatist beliefs as a mediator of cognitive impairment, negative symptoms, and functioning in schizophrenia.

Poor social and vocational outcomes have long been observed in schizophrenia. Two of the most consistent predictors are negative symptoms and cognitive impairment. We investigate the hypothesis that cognitive content--defeatist beliefs regarding performance--provides a link between cognitive impairment, negative symptoms, and poor functioning in schizophrenia. A total of 77 individuals (55 patients diagnosed with schizophrenia or schizoaffective disorder and 22 healthy controls) participated in a cross-sectional study of psychopathology. Tests of memory, abstraction, attention, and processing speed, as well as current psychopathology, functioning, and endorsement of defeatist beliefs, were employed. Greater neurocognitive impairment was associated with elevated defeatist belief endorsement, higher negative symptom levels, and worse social and vocational functioning. Notably, statistical modeling indicated that defeatist belief endorsements were mediators in the relationship between cognitive impairment and both negative symptoms and functioning. These effects were independent of depression and positive symptom levels. The results add to the emerging biopsychosocial understanding of negative symptoms and introduce defeatist beliefs as a new psychotherapeutic target.