Ks. Cadenhead et al., Sensory gating deficits assessed by the P50 event-related potential in subjects with schizotypal personality disorder, AM J PSYCHI, 157(1), 2000, pp. 55-59
Objective: The schizophrenia spectrum includes individuals with schizophren
ia, their relatives, and individuals with schizotypal personality disorder.
Subjects in the schizophrenia spectrum have disorders of attention, cognit
ion, and information processing. Attention and information processing can b
e assessed by testing suppression of the P50 event-related potential; the a
mplitude of the P50 wave is measured in response to each of two auditory cl
icks. In normal subjects, the P50 wave following the second click is suppre
ssed, or "gated." Schizophrenic patients and their relatives show less supp
ression of the second P50 wave, Deficits in P50 suppression have high herit
ability and show linkage to the alpha-7 subunit of the nicotinic cholinergi
c receptor gene in families with schizophrenia, suggesting that deficits in
P50 suppression are trait markers for gating abnormalities in schizophreni
a spectrum subjects. Although schizotypal subjects have been shown to have
deficits in sensorimotor gating as measured by prepulse inhibition, to the
authors' knowledge P50 sensory gating in schizotypal personality disorder h
as yet to be reported. Method: P50 suppression in 26 subjects with schizoty
pal personality disorder and 23 normal subjects was assessed through audito
ry conditioning and testing. Results: The subjects with schizotypal persona
lity had significantly less P50 suppression than did the normal subjects. C
onclusions: Subjects with schizotypal personality disorder may have trait-l
inked sensory gating deficits similar to those in patients with schizophren
ia and their relatives. Because these subjects may manifest sensory gating
deficits without overt psychotic symptoms, it is likely that these deficits
represent a core cognitive dysfunction of the schizophrenia spectrum.