Reduced latent inhibition in people with schizophrenia: an effect of psychosis or of its treatment.
BACKGROUND
People with schizophrenia show impaired attention. This could result from reduced latent inhibition (a measure of ability to filter out irrelevant stimuli). Previous studies have found reduced auditory latent inhibition in people with acute schizophrenia: we tested whether this results from psychosis or from drug treatment.


METHODS
We measured auditory latent inhibition in two studies. One compared antipsychotic-naive people with acute schizophrenia with patients within two weeks of starting antipsychotic treatment. The second compared healthy volunteers given either saline or 1.0 mg haloperidol, intravenously.


RESULTS
Latent inhibition was absent in treated patients, but was clearly present in patients who were naive to antipsychotics. Latent inhibition was absent in volunteers given haloperidol, but was clearly present in those given saline.


CONCLUSIONS
The reduced auditory latent inhibition seen in acute schizophrenia is more plausibly due to antipsychotic treatment than to the disorder. Unless neuropsychological models of schizophrenia incorporate evidence from drug-free patients and drug-treated healthy controls, they may be invalid.
Williams
J H
JH
Department of Pharmacology, University of Oxford.
Wellman
N A
NA
Geaney
D P
DP
Cowen
P J
PJ
Feldon
J
J
Rawlins
J N
JN
D000328:Adult; D014150:Antipsychotic Agents; D001307:Auditory Perception; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D007858:Learning; D008297:Male; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents