Recent advances in the treatment of delusional disorder

Often considered difficult to treat in the past, even treatment-resistant, delusional disorder is now regarded as a treatable condition that responds to medication in many instances. Munro and Mok previously reviewed the published record of its treatment to 1994. This review aims to update and extend their observations and to examine the impact of new second-generation antipsychotic agents on the treatment of this condition.

We attempted to gather all published reports of delusional disorder from 1994 to 2004, using various database strategies. We then assessed the reports for clarity and completeness, treatment, and outcome descriptions, thereby selecting a patient sample for analysis.

Of 224 cases identified as delusional disorder, only 134 case descriptions provided sufficient treatment and outcome data to inform this review. The demographics of this sample were similar to those of the earlier review. Depression as a comorbid condition was more frequent than before. Adherence to medication regimens was seldom explicitly addressed. Most cases showed improvement regardless of which antipsychotic medication the patients received. Pimozide and other conventional antipsychotics, as well as second-generation antipsychotics, and even clozapine, were used in many of the case reports. Family history of delusional disorder was seldom recorded.

A positive response to medication treatment occurred in nearly 50% of the cases in our review, which is consistent with the earlier review.