Cognitive effects of typical and atypical antipsychotics in schizophrenia

Abstract

The aim of the present study was to investigate the relationship between differential pharmacotherapy and cognitive functioning across an acute schizophrenic episode. We used a repeated measures design to assess neuropsychological functioning (attention, memory, executive function, motor speed) and clinical symptoms (positive symptoms, negative symptoms, general psychopathology from the SANS and BPRS) in a sample of 27 inpatients who met DSM-1II-R and SADS/RDC criteria for schizophrenia. Patients were assessed upon admission and were reassessed shortly before discharge (mean time between assessments = 17.7 days). The total sample was comprised of four subgroups based on pharmacotherapy status at the time of the two a s s e s s m e n t s ~ r o u p 1 : neuroleptic free to atypical neuroleptic (clozapine or risperidone); Group 2: neuroleptic free to typical neuroleptics; Group 3: typical neuroleptics to atypical neuroleptics; and Group 4: atypical neuroleptics to atypical neuroleptics. Significant improvement was observed across assessments for measures of verbal fluency (p = 0.004) and sustained attention (p = 0.005), which were related to time, but not to differences in pharmacotherapy status. Correlational analysis revealed that improvement in measures of memory storage and retrieval (Wechsler Memory Scale), as well as attentional flexibility (Trailmaking, Paced Auditory Serial Addition Test) were associated with clinical reduction in positive symptoms (range of r: 0.51-0.72). Improvement in general cognitive status (Mini Mental Status Examination) was associated with negative symptom reduction (r = 0.52). These findings imply that reduction in clinical symptoms, rather than type of pharmacotherapy, may predict neuropsychological improvement across an acute episode.