The studies reviewed here suggest that the potent and selective serotonin reuptake inhibitor fluvoxamine is an effective treatment for OCD. Response to the antiobsessional effects of fluvoxamine is independent of baseline levels of depression. Additional studies are currently underway to determine if fluvoxamine is actually more effective in OCD than less potent blockers of serotonin reuptake (e.g., desipramine) (Goodman et al. unpublished data). However, since the clinical response to potent serotonin reuptake blockers is often incomplete or, in as many as one-third of patients, absent, the precise relevance of the monoamine reuptake blocking properties of these medications to the pathogenesis of OCD remains unclear.