No alterations of brain GABA after 6 months of treatment with atypical antipsychotic drugs in early-stage first-episode schizophrenia

We investigated the effects of atypical antipsychotic drugs on GABA concentrations in early-stage, first-episode schizophrenia patients. Sixteen (8 males, 8 females; age, 30 ± 11 years old) patients were followed up for six months. We also included 18 sex- and age-matched healthy control subjects. All patients were treated with atypical antipsychotic drugs (5 patients with risperidone, 5 patients with olanzapine, 4 patients with aripiprazole, and 2 patients with quetiapine). In all three regions measured (frontal lobe, left basal ganglia, and parieto-occipital lobe), no differences in GABA concentrations were observed in a comparison of pre-treatment levels and those six months after treatment. These results suggest that relatively short-term treatment with atypical antipsychotic drugs may not affect GABAergic neurotransmission; however, it is also possible that such treatment prevents further reductions in brain GABA levels in people with early-stage, first-episode schizophrenia.

Research Highlights
► Brain GABA levels at least three regions (frontal cortex, left basal ganglia, and parieto-occipital lobe) did not change after 6 months treatment with atypical antipsychotic drugs.
► The pre-treatment reduction in brain GABA levels previously observed in the left basal ganglia was not reversed at 6 months treatment.
► All PANSS scores decreased after 6 months treatment with atypical antipsychotic drugs.