Rationale and objective: The relationship between clinically effective antipsychotic drugs in obsessive-compulsive disorders (OCD) and binding affinities to cloned dopamine and serotonin receptor subtypes was analyzed in an effort to clarify the contribution of individual receptor subtypes to medication response.
Methods: Meta-analysis was used to update previous meta-analyses of effectiveness data of add-on antipsychotic drugs to selective serotonin reuptake inhibitors (SSRIs) in OCD. Twelve previously analyzed randomized controlled trials (RCTs) and one new RCT were included. We performed a metaregression using a mixed-effect model to examine the association between antipsychotic's effectiveness and receptor affinity.
Results: A total of 5 treatment arms obtained from 13 RCTs (431 patients) were included in our study. The results of our metaregression showed a significant association between D2 and D3 dopamine receptor affinities and effectiveness in OCD (respectively, slope = -0.36, p = 0.01; and slope = -0.50, p = 0.01) whereas other dopamine receptors and serotonin receptors were not significantly associated.
Conclusions: These observations suggest that increasing D2 and D3 dopamine receptor binding affinities enhances antipsychotics' effectiveness in obsessive-compulsive disorders.