Risperidone, negative symptoms and cognitive deficit in schizophrenia: an open study

Abstract

The aim of this study was to evaluate the effects of a new antipsychotic compound on negative symptoms and cognitive deficit in schizophrenia. Psychiatric symptoms and cognition were assessed in 25 patients with schizophrenia, at baseline and after they had taken risperidone for 4 weeks. The Positive and Negative Symptoms Scale (PANSS), the Wisconsin Card Sorting Test (WCST) and two WAIS sub-tests were used to assess the patients. After the study period, both negative and positive symptoms and also measures of cognitive performance improved significantly. The WCST results correlated with negative symptom scores before and after treatment. This suggests that negative symptoms and cognitive deficit have a common underlying substrate which is the target of the risperidone treatment. Our data show that risperidone may have a substantial effect on complex cognitive functions in schizophrenia, and they suggest that certain cognitive deficits are relatively dependent on the negative symptoms of this disorder.

Comparison of Cognitive Performances During a Placebo Period and an Atypical Antipsychotic Treatment Period in Schizophrenia: Critical Examination of Confounds

“…The present study is consistent with previous studies demonstrating improvement in some aspects of executive function following administration of atypical antipsychotics (Buchanan et al, 1994;Gallhofer et al, 1996;Green et al, 1997;Hagger et al, 1993;Lee et al, 1994;McGurk et al, 1997;Meyer-Lindenberg et al, 1997;Rossi et al, 1997) at least to the extent that significant differences were currently obtained prior to the application of the Bonferroni correction in the current study. However, many of the tests of executive function used across studies vary widely in their task demands.…”

“…In the present study, comprehensive and marked improvement in episodic memory was also observed (especially notable were learning slope improvements). Some studies have demonstrated improvement in simple working memory performance following atypical antipsychotic administration (Galletly et al, 1997;Green et al, 1997;Rossi et al, 1997); however, our study found no difference on WMS-R digit span forward between patients receiving antipsychotic medication and the same patients receiving placebo. Our study is also consistent with many studies that have shown improvement on measures of language production (letter and category fluency) following atypical antipsychotic administration (Buchanan et al, 1994;Galletly et al, 1997;Hagger et al, 1993;Hoff et al, 1996;Lee et al, 1994;Potkin et al, 2001).…”

A preliminary investigation into the effects of antipsychotics on sub-chronic phencyclidine-induced deficits in attentional set-shifting in female rats

“…It has been widely reported that atypical antipsychotics have some beneficial effect on cognitive deficits [9,23,24,40,50]. However, it is important to appreciate the limitations of models such as this one as, although clozapine and risperidone effectively reversed the cognitive deficits observed in this experiment, the CATIE study highlights the fact that these antipsychotics do not provide consistent improvement of cognitive symptoms in patients [38].…”

Effects of Atypical Neuroleptics on Sustained Attention Deficits in Schizophrenia A Trial of Risperidone Versus Haloperidol

“…Risperidone has been reported to improve both positive and negative symptoms, with fewer propensities to elicit psychomotor side effects (Carman et al 1995;Peuskens 1995). In addition, preliminary studies have suggested that risperidone might improve a variety of neurocognitive functions, including executive function as measured by Wisconsin Card Sorting Test (Rossi et al 1997), sustained attention, delay visual recall and delayed verbal recall (Addington and Addington 1997). Thus, studies evaluating the effects of risperidone on CPT performance in schizophrenic patients might help determine whether sustained attention deficits are stable vulnerability indicators of schizophrenia.…”