• Treatment response [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Patterns of change in weight and body mass index (BMI) [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Incidence rates of metabolic syndrome and new-onset diabetes [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  

• Negative symptoms [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Cognition [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Quality of life [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Adverse events other than metabolic [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  
• Substance use [ Time Frame: Measured at Week 12 ] [ Designated as safety issue: No ]
  

Schizophrenia is a severely disabling brain disorder. People with schizophrenia often experience hallucinations, delusions, thought disorders, and movement disorders. Medications are available to alleviate the symptoms of schizophrenia, but many cause undesirable side effects. For example, two early second generation antipsychotics, olanzapine and risperidone, have been shown to be effective in treating schizophrenia symptoms, but cause rapid, substantial weight gain. There is a lower risk of such side effects with newer second generation antipsychotics, such as aripiprazole. Little is known, however, about the effectiveness of these newer medications in treating people with first-episode schizophrenia. This study will evaluate the effectiveness of aripiprazole versus risperidone for the treatment of first-episode schizophrenia.

Participants in this double-blind study will be randomly assigned to receive either aripiprazole or risperidone for 12 weeks. Additionally, all participants will take part in a Healthy Lifestyles program aimed at preventing weight gain. The Healthy Lifestyles program will provide psycho-education, supportive psychotherapy, and medication adherence counseling. Participants will report to the study site for baseline assessments upon study entry. They will then return to the study site weekly for 4 weeks, followed by once every 2 weeks for the remainder of the study. At each visit, treatment and metabolic outcomes will be assessed. Participants will meet with both a psychiatrist, who will evaluate progress and medication dosage, and a social worker, who will administer the Healthy Lifestyles Program. Blood and urine will be collected weekly for the first 4 weeks. Upon completion of the study, participants will receive follow-up care from clinical staff members who were not part of the research team.

Inclusion Criteria:

• Current DSM-IV diagnosis of schizophrenia, schizophreniform disorder, schizoaffective disorder, or similar psychotic disorder not otherwise specified, as assessed using the Structured Clinical Interview for Axis I DSM-IV Disorders (SCID-I/P)
• History of previous antipsychotic medication treatment for a duration of 2 weeks or less
• Current positive symptoms rated 4 (moderate) or more on one or more of the following Brief Psychiatric Rating Scale (BPRS-A) items: conceptual disorganization; grandiosity; hallucinatory behavior; or unusual thought content
• Agrees to use an effective form of contraception

Exclusion Criteria:

• Any serious neurological or endocrine disorder, or any medical condition or treatment known to affect the brain
• Any current medical condition that requires treatment with a medication with psychotropic effects
• At significant risk for suicidal or homicidal behavior
• Cognitive or language limitations, or any other factor that would interfere with a participant's ability to provide informed consent or safely participate in study procedures
• Diagnosis of diabetes (defined as a fasting plasma glucose level of at least 126 mg/dL) or metabolic syndrome (defined as three or more of the following: high blood pressure [greater than 135/85 mmHg]; truncal obesity [defined as having a waist circumference greater than 40 inches for men and greater than 35 inches for women]; elevated fasting glucose [defined as greater than 110 mg/dL]; low HDL-cholesterol [defined as less than 40 mg/dL for men and less than 50 mg/dL for women]; or elevated triglycerides [defined as greater than 150 mg/dL])
• Requires treatment with an antidepressant or mood stabilizing medication
• Meets DSM-IV criteria for a current substance-induced psychotic disorder, a psychotic disorder due to a general medical condition, delusional disorder, brief psychotic disorder, shared psychotic disorder, or a mood disorder (major depression or bipolar) with psychotic features
• Any medical conditions that would make treatment with risperidone or aripiprazole medically inadvisable