Schizophrenia Sensory Gating Deficit With Quetiapine

.Problems with attention and perception are core features of schizophrenia and are hypothesized to result from defects in the filtering or gating of sensory input. Examination of this requires neuoimaging techniques with high temporal resolution. High-density EEG and MEG in combination with structural magnetic resonance imaging (sMRI) are used to map sensory gating. In a number of recent studies patient treated with novel antipsychotics have been shown to have P50 gating ratios resembling those of normal controls rather than that of schizophrenia subjects treatment with conventional antipsychotics. To date, there is no literature on the effects of quetiapine on sensory gating. Subjects who meet all inclusion criteria and have been on a stable dose of quetiapine for three months will receive a clinical interview, an MRI, MEG, and neuropsychological testing to determine if patients with schizophrenia who are treated with quetiapine will demonstrate a sensory gating ratio similar to normal controls, indicating no deficit in sensory gating.

Inclusion criteria

Patient Population

• Diagnosis of Schizophrenia as determine by the Structured Clinical Interview for DSM-IV
• No comorbid diagnosis of PTSD
• responders to quetiapine, determined by continuous treatment at the same dose of quetiapine and absence of psychiatric hospitalization for at least 3 months
• No history of drug dependency in their lifetime
• No history of alcohol or other substance abuse in the 6 months prior to entry into the study
• No history of head injury with loss of consciousness for more than 5 minutes
• No history of seizure disorder
• No mood stabilizing agents
• Between 18-65 and
• Able to sign informed consent

Normal Controls

• Matched in age and gender to patient population
• No history of psychiatric dysfunction or alcohol or other substance dependence in their lifetime as determine by the SCID
• No history of alcohol or other substance abuse in the previous 6 months
• No family history of psychotic disorder in first degree relatives as assessed by the FH-RDC diagnostic interview
• No history of head injury with loss of consciousness for more than 5 minutes
• No history of seizure disorder
• Between 18-65
• Able to sign informed consent

Exclusion criteria

Subjects will be excluded from participating in this study if they:

• Require treatment with a mood stabilizer
• Have had an inpatient hospitalization in the past 3 months
• Have a history of a neurological disorder
• Have any other axis I diagnosis besides schizophrenia