tokens: RESULTS : The mean + / - SD duration of treatment with the identified atypical antipsychotic agent was 68 . 3 + / - 28 . 9 months ( clozapine ) , 29 . 5 + / - 17 . 5 months ( olanzapine ) , and 40 . 9 + / - 33 . 7 ( risperidone ) .