The influence of switching from haloperidol decanoate depot to risperidone long‐acting injection on the clinical symptoms and cognitive function in schizophrenia

Abstract

This study was a comparative investigation of the effects on clinical symptoms and cognitive function of switching the treatment of schizophrenia patients from haloperidol decanoate depot to risperidone long-acting injection (RLAI) compared with a control group that continued receiving haloperidol decanoate depot. This study was a 24-week, non-randomized, non-double blind, open-label trial. The subjects' clinical symptoms were assessed using the Positive and Negative Syndrome Scale, and their cognitive function was assessed using the Wisconsin Card Sorting Test: Keio Version to assess executive function and the St. Marianna University School of Medicine's Computerized Memory Test to assess memory and concentration at 0 and 24 weeks. The mean change from baseline in the number of categories achieved at the second stage of the Wisconsin Card Sorting Test: Keio Version was significantly greater in the RLAI group than in the control group. The mean changes from baseline in the individual St. Marianna University School of Medicine's Computerized Memory Tests were significantly greater in the RLAI group than in the control group. The RLAI group needed a lower dosage of biperiden compared with the control group, even though they had similar risperidone-equivalent daily dosages. The results of this study suggest the possibility that switching from haloperidol decanoate depot to RLAI may improve cognitive function including memory, executive function, motor processing function, and attention.