Sustained attention and positive formal thought disorder in schizophrenia.

Deficits in sustained attention and formal thought disorder (FTD) are two characteristics of schizophrenia that might be expressions of a common pathology. This study examined whether a measure of enduring (post-treatment, stabilized) deficits in sustained attention, the Continuous Performance Test (CPT) could predict FTD. In addition, a comparison was made of CPT performance between subjects with schizophrenia (n = 41) and healthy controls (n = 28). Results replicated previous findings of significantly poorer performance by individuals with schizophrenia compared to normal controls. Within the schizophrenia group, significant correlations were found between FTD and CPT measures. In order to assess predictability of FTD, a hierarchical multiple regression analysis was used. CPT errors and gender both significantly predicted FTD. The most robust prediction was of residual FTD (post-treatment, stabilized) by CPT commission errors. These results lend support to the proposition that a subsyndrome within schizophrenia exists that is characterized by deficits in sustained attention and positive formal thought disorder. Furthermore, this subsyndrome might be more common in males than females.