OCD is a common disorder, affecting 1% of the population and usually responds to treatment with serotonin reuptake inhibitors (SRIs) or exposure and response prevention (ERP) and to augmentation with antipsychotics. However, some patients fail to respond. The national inpatient unit for obsessive compulsive disorder (OCD) and body dysmorphic disorder (BDD) (i) is the only 24-hour staffed inpatient facility for OCD in the UK and treats patients with profound, treatment-refractory OCD. There is evidence of efficacy of aripiprazole in augmenting SRI sin severe OCD (ii).

To compare the efficacy of aripiprazole versus other antipsychotics as SRI augmentation.

One hundred and nine patients admitted to the unit between March 2006 and September 2011 and discharged on an antipsychotic and an SRI were included. The Yale-Brown obsessive compulsive scale (YBOCS) was administered at admission and at discharge. Data were analysed using SPSS version 23 using analysis of variance (ANOVA). Two groups were compared: those receiving SRI+aripiprazole versus those receiving SRI+another antipsychotic.

sixty-two patients received SRI with aripiprazole and 47 SRIs with another antipsychotic. Overall, patients showed improvement, with an average YBOCS reduction of 11.7 (33% reduction). Patients taking aripiprazole improved by an average of 13 (36% reduction, P<0.05).

Patients of the national unit with severe, treatment refractory OCD treated with aripiprazole augmentation showed a greater improvement than those on other antipsychotics. Further research into aripiprazole in OCD is warranted.