Risperidone for the treatment of delusional disorder

The overlap between diagnostic criteria for schizophrenia and delusional disorder (DD) may cause diagnostic confusion. This is important if response to treatment differs. Risperidone, an atypical antipsychotic, is established in the treatment of schizophrenia, although less so in other psychotic conditions.

We report the case of a woman who developed DD, persecutory type, at the age of 50 years. Treatment with sulpiride 200-800 mg daily caused side-effects of drowsiness and 'hangover' and, consequently, non-compliance. Written informed consent was gained for a 24-week, randomized, double-blind, placebo-controlled, crossover trial of risperidone, initiated at 1 mg daily and increasing to 2 mg daily.

Significant improvement was found, as assessed by the Brief Psychiatric Rating Scale, Positive and Negative Symptom Schedule and Maudsley Assessment of Delusions Schedule.

We believe that this is the first case study reporting the resolution of persecutory DD with risperidone. A controlled clinical trial of risperidone in the treatment of patients with DD is warranted. (Int J Psych Clin Pract 2002; 6: 113-116).