Decreased language lateralization is characteristic of psychosis, not auditory hallucinations.
BACKGROUND Quetiapine improves both psychotic symptoms and cognitive function in schizophrenia. The neural basis of these actions is poorly understood. METHODS Three subject groups underwent a single functional magnetic resonance imaging (fMRI) session: drug-naive (n = 7) and quetiapine-treated samples of patients with schizophrenia (n = 8) and a healthy control group (n = 8). The fMRI session included an overt verbal fluency task and a passive auditory stimulation task. RESULTS In the verbal fluency task, there was significantly increased activation in the left inferior frontal cortex in the quetiapine-treated patients and the healthy control sample compared with the drug-naive sample. During auditory stimulation, the healthy control group and stably treated group produced significantly greater activation in the superior temporal gyrus than the drug-naive sample. CONCLUSIONS Quetiapine treatment is associated with altered blood oxygen level-dependent responses in both the prefrontal and temporal cortex that cannot be accounted for by improved task performance subsequent to drug treatment.