EFFECTIVENESS OF RISPERIDONE AUGMENTATION IN OBSESSIVE-COMPULSIVE DISORDER – EXPERIENCE OF A SPECIALTY CLINIC IN INDIA

Abstract

Background Randomized placebo-controlled trials suggest that risperidone may be efficacious as an add-on treatment to serotonin reuptake inhibitors (SRIs) in patients with obsessive compulsive disorder (OCD). Inherent limitations of these studies are the relatively small sample sizes and concern over their generalizability to real-world clinical practice. Also, factors predicting response to risperidone augmentation are unclear. Aim To assess the effectiveness of risperidone augmentation in OCD, and to study the predictors of response, in a real-world setting. Method 1314 consecutive patients who consulted a specialty OCD clinic between 2004 and 2014 at a large psychiatric hospital in India were evaluated with Mini International Neuropsychiatric Interview, the Yale-Brown Obsessive–Compulsive Scale, and the Clinical Global Impression scale. Patients with OCD initiated on risperidone, not having psychosis or mental retardation, without ongoing cognitive behavior therapy and who were on stable SRI medication for at least 12 preceding weeks were included for analysis. Primary outcome measure was all-cause discontinuation. Principal component analysis with Varimax rotation was conducted utilizing responses from YBOCS checklist, which yielded a 5-factor solution with the following dimensions - ‘pathological doubts/checking’, ‘need for symmetry/orderliness’, ‘forbidden thoughts’, ‘cleaning/contamination’, and ‘hoarding’. Predictors of treatment response were evaluated by logistic regression analysis (backward wald) with symptom dimensions and other relevant antecedent variables as independent variables and all-cause discontinuation as the dependent variable. Results 104 patients were eligible for analysis. In all except 24 patients (23.08%), risperidone had been discontinued at the time of last follow-up, either due to ineffectiveness or intolerability. 26 patients (25%) were noted to have at least 25 % reduction on YBOCS. 24 patients (23.08%) were marked either as ‘much improved’ or ‘very much improved’ on CGI-I. Mean reduction in YBOCS scores for the whole sample (n=104) was 13.54% (t=5.45, p On regression analysis, ‘forbidden thoughts’ predicted discontinuation of risperidone (p=0.021). Conclusions Risperidone proved to be an effective augmenting agent in a significant sub-set of patients with OCD. The drug may be less beneficial in patients with ‘forbidden thoughts’ (sexual, religious, or aggressive obsessions).