Effect of Risperidone on Behavioral and Psychological Symptoms and Cognitive Function in Dementia

Aims: This open-label study examined the efficacy and tolerability of risperidone in the treatment of aggression, agitation, and psychotic symptoms in dementia. The influence of risperidone on cognitive function was also assessed under conditions reflecting normal, daily clinical care.

Method: A total of 34 hospital inpatients and outpatients (mean age = 76 years) with DSM-IV dementia disorders were treated with flexible doses of risperidone (0.5-2 mg/day) for 8 weeks. Assessments, conducted at baseline and after weeks 4 and 8, included the Clinical Global Impressions scale (CGI) and Neuropsychiatric Inventory (NPI) ratings. Cognitive function assessments included the Mini-Mental State Examination (MMSE) and specific measures of cognition (Age Concentration Test [AKT] and Brief Syndrome Test [SKT]). Frequency of extrapyramidal symptoms (EPS) was measured according to the Extrapyramidal Symptom Rating Scale (ESRS).

Results: At the end of the study, 50% of patients (N = 17) were receiving risperidone,1 mg/day, 18% (N = 6) were receiving 0.5 mg/day, and 32% (N = 11) received > 1 mg/day (mean dose at endpoint = 1.1 mg/day). An improvement in symptoms, as measured by the CGI-Global Impression of Change scale, was reported for 82% of patients (N = 28) (59% [N = 20] much or very much improved). The frequency and severity of delusions, hallucinations, agitation/aggression, and irritability decreased as measured by the NPI. Multiplication of frequency and severity scores revealed a significant decline during the course of treatment (p < .001, end of study vs. baseline). Caregiver responses on the NPI also showed an improvement, with the mean ± SD total score decreasing from 24.2 ± 7.3 at baseline to 21.2 ± 6.3 at study end (p = .002). MMSE, AKT, and SKT results indicated that there was no decrease in cognitive function during the study. Risperidone treatment was well tolerated, and no clinically relevant changes in EPS, vital signs, or weight were detected.

Conclusion: During treatment with low-dose risperidone, behavioral and psychological symptoms improved overall in 34 patients with dementia, and cognitive function was maintained throughout the treatment period.