Social Cognition Mediates the Impact of Processing Speed and Sustained Attention on Global Functioning in Schizophrenia.

Background: Deficits in information processing, sustained attention and social cognition have important implications for the daily functioning of people with schizophrenia. The present study analyzed the relationship between processing speed, sustained attention, social cognition, and functioning in clinically stable people with schizophrenia.

Method: Ninety people with schizophrenia and 100 healthy controls completed a battery of measures to assess clinical symptoms, processing speed, sustained attention, social cognition, and functioning. GLMMs and SEM were used to assess the relationships between these variables.

Results: People with schizophrenia had impaired performance in all cognitive outcomes compared to healthy controls. Processing speed and sustained attention, together in a latent variable, had a strong effect on functioning (Beta = 0.32; p <.05). However, social cognition had also a strong effect on functioning (Beta = 0.29; p <.001) in the mediation model, which exhibited better indices of fit than the model including neurocognition alone (e.g. RMSEA_basic = 0.131 and RMSEA_mediator = 0.054).

Conclusions: The mediating effect of social cognition on the relationship between processing speed, sustained attention, and functioning in people with schizophrenia suggests the importance of including both domains of neurocognition along with social cognition as treatment targets in rehabilitation interventions to optimize improvements in functioning in schizophrenia.