Modulation of the startle response and startle laterality in relatives of schizophrenic patients and in subjects with schizotypal personality disorder: Evidence of inhibitory deficits

Objective: Patients with schizophrenia spectrum disorders have been shown t o have deficits in sensorimotor gating as assessed by prepulse inhibition o f the startle response. The authors hypothesized that nonschizophrenic rela tives of patients with schizophrenia would also have prepulse inhibition de ficits, thereby reflecting a genetically transmitted susceptibility to sens orimotor gating deficits. Method: Twenty-five comparison subjects. 23 patients with schizophrenia, 34 relatives of the schizophrenic patients, and 11 subjects with schizotypal personality disorder were assessed in an acoustic startle paradigm. The eye -blink component of the startle response was assessed bilaterally by using electromyographic recordings of orbicularis oculi. Results: The patients with schizophrenia, their relatives, and subjects wit h schizotypal personality disorder ail had reduced prepulse inhibition rela tive to comparison subjects, and these deficits were more evident in measur es of right eve-blink prepulse inhibition. Comparison subjects demonstrated greater right versus left eye-blink prepulse inhibition, whereas the proba nds, their relatives, and subjects with schizotypal personality disorder sh owed less asymmetry of prepulse inhibition. Conclusions: These data suggest a genetically transmitted deficit in prepul se inhibition (sensorimotor gating) in patients with schizophrenia spectrum disorders, including subjects with schizotypal personality disorder and re latives of patients with schizophrenia.