Conditions: Schizophrenia
Keywords: Schizophrenia Antipsychotic drug treatment response Risperidone Aripiprazole Fallypride Positron emission tomography Magnetic Resonance Imaging Dopamine D2 Receptors
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 21
Healthy volunteers: no

Brief summary:
This study is being conducted to find a way to predict how individual schizophrenic patients will respond if they are treated with different types of antipsychotic drugs. This could help doctors prescribe the medication that will work best for each individual.

Detailed description:
The primary objective of the proposed research project is to identify a practical method of predicting differential antipsychotic drug treatment response in patients with schizophrenia. In particular, we will examine differential response to two antipsychotic drugs, aripiprazole and risperidone, that have contrasting pharmacologic activity at D2-type dopamine receptors, i.e., partial agonism vs. antagonism, respectively. A number of candidate predictors will be examined, including neuroimaging parameters (regional neuroanatomical and metabolic variations, fallypride binding to D2-like receptors), neuropsychological testing, clinical features, laboratory measures, and genetic studies.

Secondary objectives include: (1) extension of our previous efforts to characterize abnormalities in cortico-striato-thalamic circuits in unmedicated schizophrenics using PET and MR imaging; and, (2) examination of the role of omega-3 fatty acid activity in schizophrenics as a predictor of dopaminergic activity.

Arms:
arm 1: Screening and Baseline Procedures followed by Referral to Community Care. Baseline Procedures may be repeated at a later time if appropriate. arm 2: Screening and Baseline Procedures followed by 16 weeks of treatment with aripiprazole, followed by repeat of baseline procedures and referral to community care. arm 3: Screening and Baseline Procedures followed by 16 weeks of treatment with Risperidone,followed by repeat of baseline procedures and referral to community care.

Interventions: intervention 1: Aripiprazole intervention 2: Risperidone
Intervention descriptions: intervention 1: Target dose = 15mg by mouth per day for 16 weeks. The dosage will be titrated in accordance with the treating physician's clinical judgment, generally reaching full dosage within one week of initiation. The dosage may be increased as clinically indicated, by the treating physician. Any deviation from these target dosing schedules must be reviewed and approved by the principal investigator, generally prior to the adjustment unless clinical circumstances require more immediate adjustment (in which case the treating physician should consult with the principal investigator as soon as is practically possible). intervention 2: Target Dose = 2mg by mouth per day for 16 weeks. The dosage will be titrated in accordance with the treating physician's clinical judgment, generally reaching full dosage within one week of initiation. The dosage may be increased as clinically indicated, by the treating physician. Any deviation from these target dosing schedules must be reviewed and approved by the principal investigator, generally prior to the adjustment unless clinical circumstances require more immediate adjustment (in which case the treating physician should consult with the principal investigator as soon as is practically possible).

Protocol document: