Long-Term Treatment with Antipsychotics Affects NAA T1 in Normal Rat Brain

Diana M. Lindquist¹, R S. Dunn¹

Multiple MRS studies have been reported comparing schizophrenic patients and normal subjects, with mixed results. Differences between normal subjects and patients may be due to changes in either water or metabolite relaxation times. Changes in relaxation times could result from the disease and/or the drugs used to treat it. In this 6-month study, we found that NAA T1 times in normal rat brain are significantly shorter for rats treated with either haloperidol or clozapine. Long term treatment with antipsychotics appears to decrease NAA T1 values, which may result in an overestimation of the NAA concentration in treated schizophrenic patients.