• Score on attenuated positive symptom scale at 16 weeks
  
• Score on attenuated negative symptom scale at 16 weeks
  

• Score on social functioning measure at 16 weeks
  
• Score on academic functioning measure at 16 weeks
  
• Score on cognitive measures at 16 weeks
  

Eligible patients are enrolled in a 16-week trial consisting of symptom and side effects ratings (10 visits), monthly blood and urine tests, and neuropsychological testing at the first and last visits. At the initial appointment, all patients are assigned to sertraline and are randomly assigned to an adjunctive risperidone or placebo group. The treating physician is also blind to the medication assignment, which allows both the doctor and the patient to assess side effects and symptom improvement, unbiased by expectation. All patients receive an active medication.

Inclusion Criteria:

• Participants are between the ages of 12 and 22.
• Participants are English-speaking.
• Participants are experiencing one or more symptoms like unusual thoughts, suspiciousness, or unusual perceptual experiences.
• Participants meet additional RAP criteria (evaluated during screening and interview).

Exclusion Criteria:

• Participants have been diagnosed with an Axis I psychotic disorder, including: schizophreniform disorder, schizophrenia, schizoaffective disorder, bipolar disorder, or major depression with psychotic features.
• Participants have a history of neurological, neuroendocrine, or other medical conditions known to affect the brain.
• Participants have a medical condition that contraindicates treatment with sertraline or risperidone.
• Participants have past or current substance dependence.
• Participants are currently taking and responding well to antidepressant or antipsychotic medication