Favourable results in treatment-resistant schizophrenic patients under combination of aripiprazole with clozapine

Clozapine is still the gold standard in treatment-resistant schizophrenia. However, a substantial amount of patients do not fully recover on clozapine monotherapy. Though there is still a lack of randomised controlled studies of combination strategies in treatment-resistant schizophrenia, they are widely used. Aripiprazole is a relatively new therapeutic option due to its partial D2 agonism. Both clozapine and aripiprazole, though having a generally favourable side-effect profile, may lead to insufficient response and might provoke side effects in monotherapy. We report the case of four patients in whom we observed a distinct clinical improvement with respect to positive and negative symptoms without major side effects under a combination of clozapine and aripiprazole. The combination of clozapine action and aripiprazole-mediated D2 receptor regulation could be responsible for the described favourable effects and for the increase of D2 receptor blockade after adding aripiprazole to clozapine observed in o...