As many as 75 percent of patients with schizophrenia have difficulty taking their oral medication on a regular basis. This may lead to worsening of symptoms. Clinicians commonly respond to these problems by adding adjunctive medications, despite the absence of systematic studies that support such practices. It is possible, however, that in many of these cases, the unstable course and/or unsatisfactory treatment response reflects incomplete adherence with the originally prescribed oral antipsychotic, rather than a need for adjunctive medications. This study will examine whether switching patients who demonstrate an unstable course and/or an unsatisfactory clinical response to a long-acting injectable preparation as the primary antipsychotic may enhance medication adherence and improve outcomes.