Introduction: The measurement of the intellectual capacity (IC) in schizophrenic patients has been found to be of clinical relevance. A user-friendly tool such as the Cattell's intelligence test might facilitate this measurement in daily clinical practice.
Method: In this study, we measured the intelligence quotient (IQ) using Cattell's test in 35 schizophrenic patients before and after treatment with risperidone.
Results: At baseline, the sample showed an average intelligence of 78.3 points (standard deviation [SD]: 14.3), in the low-medium range. After 1 year on risperidone, the IQ significantly improved (mean: 84.8; SD: 17.0; p = 0.028). This IQ elevation was positively correlated with the improvement in the psychotic symptoms rated with the PANSS.
Conclusions: Cattell's intelligence test could be a valid instrument to measure cognitive performance in schizophrenic patients. Antipsychotic therapy with risperidone could be effective to improve cognitive functioning in these subjects.