Objectives: The aim of this study was to assess the specific features of attention impairment in patients with schizophrenia and the correlation between those features and the patients' clinical status.
Methods: We administered the Conners Continuous Performance Test (CPT-II), with cognitive and clinical scales, to 40 Spanish inpatients with schizophrenia and 40 healthy controls, and used a cross-sectional design to compare the groups' performances. We identified correlations between the measures and used multiple regression analyses to develop models showing how attention impairment contributed to clinical status.
Results: The patients with schizophrenia showed significantly poorer performance than controls in 5 CPT-II measures that were related to focused attention. We also found that CPT-II measures primarily linked to focused attention had a significant association with negative symptoms. These CPT-II measures predicted 37% of the variability in negative symptoms in the regression model. We observed a more modest relationship among CPT-II measures of disorganized thought symptoms, global functioning, and general cognitive performance.
Conclusions: Attention impairment in schizophrenia primarily involves difficulty in focusing attention, mainly related to negative symptoms. By contrast, sustained attention and vigilance seem to be affected only as a secondary consequence of the impairment to focusing attention.