Published online Apr 19, 2020. doi: 10.5498/wjp.v10.i4.34
Peer-review started: December 27, 2019
First decision: February 20, 2020
Revised: March 4, 2020
Accepted: March 22, 2020
Article in press: March 22, 2020
Published online: April 19, 2020
Delusional disorder (DD) has been traditionally considered a relatively rare and treatment-resistant psychotic disorder. In the last decade, increasing attention has focused on therapeutic outcomes of individuals affected by this disorder. The aim of this paper is to provide a synthesis of the literature addressing two very important questions arising from DD research: (1) For which patients with DD do antipsychotic medications work best (the moderators of response); and (2) What variables best explain the relationship between such treatments and their effectiveness (the mediators of response). We searched PubMed and Google Scholar databases for English, German, French and Spanish language papers published since 2000. We also included a few classic earlier papers addressing this topic. Variables potentially moderating antipsychotic response in DD are gender, reproductive status, age, duration of illness, the presence of comorbidity (especially psychiatric comorbidity) and its treatment, brain structure, and genetics of neurochemical receptors and drug metabolizing enzymes. Antipsychotic and hormonal blood levels during treatment, as well as functional brain changes, are potential mediating variables. Some, but not all, patients with DD benefit from antipsychotic treatment. Understanding the circumstances under which treatment works best can serve to guide optimal management.
Core tip: Although patients with delusional disorder have traditionally been viewed as treatment-resistant, many do experience benefits from antipsychotic medications, but not all respond similarly. The identification of mediators and moderators of treatment response is clinically useful in that understanding under what circumstances treatment works best provides a reliable guide to effective management.