Efficacy of Risperidone in Enhancing Cognitive Functions in Psychiatric Disorders: A Systematic Review and Meta-analysis
Authors: Almurayeh Khalid Nassir , Aleid Ahmed Fadeil , Alqahtani Dina Fares , Alharbi Fatimah Raja , Alkhudhayr Ibtihal Ibrahim , Alyousef Maha Saleh , Ahmari Raghad Mushabab Al , Khoja Rahaf Hussam , Alawad Fatema Hani , Mohaini Mohammad Al 
Published: December 2024

Abstract

Background:
Schizophrenia affects about 1% of the global population, with cognitive impairments significantly impacting patients’ quality of life. Risperidone, a second-generation antipsychotic, is commonly used to treat schizophrenia, known for its efficacy in reducing symptoms and potential cognitive benefits. However, the extent of its impact on cognitive functions remains unclear due to inconsistencies in the literature, necessitating a systematic review and meta-analysis to better understand these effects.

Materials and Methods:
Following Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines, we systematically reviewed clinical randomised trials and cohort studies evaluating the efficacy of risperidone on cognitive functions in schizophrenia. A comprehensive literature search was conducted in PubMed, Scopus, Web of Science and the Cochrane Library. The quality of included studies was assessed using the risk of bias 2 tool and the Newcastle–Ottawa Scale.

Results:
Eleven studies with 649 patients were analysed. Significant cognitive improvements were observed in several domains: positive and negative syndrome scale (n = 228, standardised mean difference [SMD] = −0.44, 95% CI [−0.70, −0.17], P = 0.001), verbal learning (n = 98, SMD = 0.67, 95% CI [0.26, 1.09], P = 0.001) and Trails B (n = 124, SMD = −1.02, 95% CI [−1.28, −0.75], P < 0.00001). Wisconsin Card Sorting Test perseverations showed a reduction in errors (n = 792, SMD = −0.14, 95% CI [−0.28, −0.0], P = 0.05), and Wechsler Memory Scale-Revised Logical Memory tests, both immediate (n = 272, SMD = 0.53, 95% CI [0.28, 0.78], P < 0.0001) and delayed recall (n = 288, SMD = 0.48, 95% CI [0.24, 0.72], P < 0.0001), indicated improvements. Attention and processing speed also improved significantly (n = 98, SMD = 0.69, 95% CI [0.27, 1.11], P = 0.001). However, no significant effects were observed for working memory (n = 368, SMD = −0.02, 95% CI [−0.23, 0.19], P = 0.85), verbal fluency (n = 456, SMD = 0.04, 95% CI [−0.14, 0.22], P = 0.67), Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design (n = 78, SMD = 0.35, 95% CI [−0.10, 0.80], P = 0.13), WAIS-R digit symbol (n = 170, SMD = 0.22, 95% CI [−0.09, 0.52], P = 0.16) or motor function (n = 74, SMD = 0.27, 95% CI [−0.20, 0.75], P = 0.26).

Conclusions:
Our meta-analysis indicates that risperidone significantly improves cognitive functions in psychiatric disorders especially schizophrenia, particularly in areas related to attention, processing speed, executive function and memory recall. These findings highlight the potential of risperidone beyond its primary antipsychotic effects. Further research with larger and more diverse populations is needed to confirm these findings and explore the long-term impact of risperidone on cognitive functions.