Practice-related improvement in information processing with novel antipsychotic treatment

Background: Attentional deficits are prominent in schizophrenia, and skill learning is impaired. Novel antipsychotic treatment has been reported to improve certain cognitive skills in schizophrenic patients, but no information is yet available about the effect of newer medications on skill learning. Methods: Clinically stable patients with schizophrenia (n=16) and chronically hospitalized inpatients (n=8) were recruited while receiving conventional antipsychotic treatment. Subjects were tested at baseline on a visual continuous performance test (CPT), performed alone and simultaneously with an auditory CPT. Normal controls (n=8) were also tested at baseline. The inpatients and half of the outpatients were switched to treatment with risperidone. All patients then performed the visual CPT on a daily basis and performed the dual tasks once per week, for 4weeks. Results: Patients who remained on conventional medications did not improve in their performance despite the extensive practice on the test. Both chronic and stable patients receiving risperidone treatment manifested a statistically significant (P<0.05) improvement from baseline on both single and dual-task visual CPT. Stable outpatients performed significantly better at the end of the protocol than the normal controls performance at baseline (P<0.05). Implications: These results suggest that practice-related improvements in the performance of information processing tests are enhanced by novel antipsychotic medications. Although the specific biological mechanism of this effect is not yet known, the results may suggest that use of newer medications will enhance skill development and perhaps facilitate rehabilitation of patients with schizophrenia.