A typical antipsychotics normalize low-gamma evoked oscillations in patients with schizophrenia

ABSTRACT

The symptoms of schizophrenia might be mediated by a cortical network disconnection which may disrupt the cortical oscillatory activity. Steady-state responses are an easy and consistent way to explore cortical oscillatory activity.

A chirp-modulated tone (increasing the frequency of the modulation in a linear manner) allows a fast measure of the steady-state response to different modulation rates. With this approach, we studied the auditory steady-state responses in two groups of patients with schizophrenia (drug-naive and treated with atypical antipsychotic drugs), in order to assess the differences in their responses with respect to healthy subjects, and study any potential effect of medication.

Drug-naive patients had reduced amplitude and inter-trial phase coherence of the response in the 30-50Hz range, and reduced amplitude of the response in the 90-100Hz range, when compared to controls. In the treated patients group, the response in the 30-50Hz range was normalized to values similar to the control group, but the reduction in amplitude in the 90-100Hz range remained as in the drug-naive group.

These results suggest that gamma activity impairment in schizophrenia is a complex phenomenon that affects a wide band of frequencies and may be influenced by antipsychotic treatment.

CITATION  Psychiatry Res. 2016 Nov 26;247:214-221. doi: 10.1016/j.psychres.2016.11.030