Obsessive-compulsive symptoms (OCSs) are frequently comorbid with schizophrenia. Various atypical antipsychotics induce OCSs by 5-HT2A receptor inhibition. Amisulpride causes only minimal inhibition of the 5-HT2A receptor, and therefore, should not induce or exacerbate OCSs in patients with schizophrenia.

To evaluate the efficacy and tolerability of amisulpride on OCSs in patients with schizophrenia who were taking typical or atypical antipsychotics.

21 patients, aged 18-65 years, with schizophrenia and OCSs (DSM-4 criteria) with a score of 16 or higher on YBOCS and taking a single antipsychotic were enrolled to a 12-week prospective open trial of amisulpride (400-1200 mg/d). Changes in YBOCS, PANSS,CGI,GAF QLS -18, extrapyramidal symptoms, adverse events, and body-weight changes were evaluated 12 weeks after the antipsychotics were switched to amisulpride.

All 19 patients who completed the trial had an improvement on the YBOCS,PANSS,CGI,GAF AND QLS-18. At week 12,the mean YBOCS total score decreased significantly (26.579 ± 5.124 vs.14.631± 5.479; p < 0.001),the mean PANSS total score decreased significantly (83.947±17.886 vs.63.421±14.311; p < 0.001). Eight patients (42.1%) showed 50% or more improvement in the YBOCS total score. Thirteen patients (68.4%) showed 20% or greater improvement in the PANSS total score. Amisulpiride was safe and well tolerated.

These results indicate that switch to amisulpiride is very effective for OCSs, psychotic symptoms and global functioning in patients with schizophrenia.However, changes in OCSs and psychotic symptoms were independent. Further studies with amisulpiride under controlled conditions are needed for these patients.