The purpose of this study is to gather systematic clinical data on whether aripiprazole, a partial dopamine agonist, beneficially affects schizophrenia plus cocaine dependence subjects. Since aripiprazole has established effects against schizophrenia, the study focuses on whether aripiprazole concurrently reduces co-morbid cocaine dependence in schizophrenia plus cocaine dependence sufferers compared to a standard typical antipsychotic treatment (perphenazine). The working hypothesis states that subjects in the aripiprazole treatment arm of the study will give fewer cocaine positive urine specimens as compared to the perphenazine control arm.