ABSTRACT
Objective To compare the effects of typical and atypical antipsychotics treatment on P50 sensory ga-ting in first-episode schizophrenics.Methods Using conditioning-testing stimulus paradigm and stimulus train paradigm to record the P50 auditory evoked potential in 36 normal controls and in 61 first-episode schizophrenics before and after treat-ment.Patients were categorized into two groups:the typical antipsychotic treatment group(typical group)and the atypical antipsychotic treatment group(atypical group).Results Before treatment,both of the typical and atypical groups had low-er levels of S2-P50 amplitude,P50 suppression in conditioning-testing stimulus paradigm and P50 amplitude as well as P50 suppression evoked by high frequency stimuli in stimulus train paradigm in comparison with controls(P<0.05).After treatment,the typical antipsychotic treatment significantly improved the levels of P50 suppression in the stimulus train para-digm but not the levels of S2-P50 amplitude,P50 suppression in the conditioning-testing stimulus paradigm(P<0.05)whereas the atypical antipsychotic treatment improve the levels of P50 amplitude,P50 suppression in both stimulus train paradigm and the conditioning-testing stimulus paradigm(P<0.05). Conclusions The typical antipsychotic treatment can ameliorate the P50 suppression in stimulus train paradigm,but not in the conditioning-testing stimulus paradigm,whereas atypical antipsychotic treatment can ameliorate P50 suppression in both paradigms.