• delirium;
  • Delirium Rating Scale (DRS);
  • elderly;
  • risperidone


Background:  Despite increasing recognition of delirium as a serious complication of physical illness, little has been reported in this area. Interest has been raised in treatment options other than haloperidol, such as atypical antipsychotic agents.

Methods:  A 2-week open-label trial of risperidone for the treatment of delirium was conducted to assess the efficacy and tolerance of this medication in elderly patients. Twenty-two patients with DSM-IV-defined delirium were investigated. All patients had the hyperactive–hyperalert variant of delirium. Patients received a fixed dose of risperidone (mean 1.5 ± 0.7 mg; range 0.5–3 mg). Delirium was assessed using the Delirium Rating Scale (DRS) at baseline and on Days 1, 3, 5, 7, and 14 after the initiation of risperidone treatment. Clinical and demographic data, as well as risperidone therapy related information, were collected.

Results:  Delirium resolved in all patients over the course of treatment. The mean period over which delirium resolved was 4.0 ± 2.9 days. The mean DRS score at baseline was 20.7 ± 3.0. The DRS score improved from baseline to Day 1 of treatment and continued to improve until the study end-point. Mild side-effects were present in 27.3% of patients. Stepwise logistic regression identified a decrease of 2 points or higher on the DRS on Day 1 associated with side-effects. There were no significant differences in the response to treatment with the different doses of risperidone used.

Conclusion:  Our findings indicate that low-dose risperidone (0.5–3.0 mg/day) is effective and safe for the treatment of delirium in elderly patients, and that an early response on Day 1 of treatment may be associated with side-effects in these patients.