 This study design is subject to relevant SFDA regulations about clinical trials. Patients will be screened for inclusion into the study at the initial visit240 patients to be recruited and then undergo a minimum of 3-7 days placebo washout periodplacebo wash out is to eliminate the effect of prior antipsychotic medication with tablets without any active ingredientspatients without prior antipsychotic medication are exempt from the washout phase. After screening and washout period, eligible patients will be randomly assigned to the two treatment group, Aripiprazole or Risperidone, for 6 weeks treatment. Patients will be hospitalized for the entire duration of the study. Patients condition will be assessed weekly. 