A substantial proportion of people with schizophrenia do not respond adequately to commonly used antipsychotic medications. These patients are at high risk for a wide range of poor outcomes, including victimization, homelessness, incarceration, hospitalization, or death. Clozapine has been found to be more effective than other antipsychotic medications when patients are treatment-resistant. Researchers have also found that clozapine results in greater patient adherence and lower suicide risk. Per the U.S. F.D.A., clozapine is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. While there is no commonly accepted definition of failure to respond adequately, some research studies have defined this as failure to respond to two trials of antipsychotic medication of at least 6 weeks duration at an adequate dose. Clozapine is also indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for re-experiencing suicidal behavior. U.S. treatment guidelines for schizophrenia recommend clozapine for patients who are treatment-resistant, and for patients who have risk for suicide attempts or suicide that remains substantial despite other treatments. Guidelines suggest clozapine if patients have risk for aggressive behavior that remains substantial despite other treatments.