Information processing deficits in acutely psychotic schizophrenia patients medicated and unmedicated at the time of admission.
OBJECTIVE
In patients with schizophrenia, information processing deficits, such as those reported in studies that measured prepulse inhibition of the human startle response and habituation of startle magnitude, may be improved with atypical antipsychotic treatment. However, it remains unclear whether antipsychotic medication is directly responsible for the improvement or whether differences in prepulse inhibition reflect other factors, such as acuity status. The present study investigated the effects of antipsychotics on prepulse inhibition and startle habituation in acutely hospitalized patients with schizophrenia.


METHODS
Forty-one acutely psychotic schizophrenia patients (21 who were unmedicated at the time of admission and 20 who had been receiving antipsychotic treatment) were tested within 72 hours of hospital admission. Thirteen healthy subjects were also studied for comparative purposes. Primary dependent measures were startle responsivity, reactivity, prepulse inhibition, and startle habituation.


RESULTS
Schizophrenia patients, whether medicated or unmedicated at admission, showed prepulse inhibition deficits compared with healthy subjects and did not statistically differ from each other in startle magnitude, prepulse inhibition, or habituation. There was a higher number of startle "nonresponders" among those who had been receiving medication versus those unmedicated at the time of admission.


CONCLUSIONS
The present findings suggest that antipsychotic effects on prepulse inhibition may not be evident at a time when schizophrenia patients are acutely symptomatic. These results suggest that the neurobiological substrate underlying prepulse inhibition deficits may be dysregulated during acute psychotic states while the patients are in early phases of medication treatment.
Perry
William
W
Neuropsychiatry and Behavioral Medicine Service, Department of Psychiatry, University of California San Diego, La Jolla 92093-8620, USA. wperry@ucsd.edu
Feifel
David
D
Minassian
Arpi
A
Bhattacharjie
Indira
I
Braff
David L
DL
D000161:Acoustic Stimulation; D000208:Acute Disease; D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D005260:Female; D006185:Habituation, Psychophysiologic / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D008297:Male; D013216:Reflex, Startle / Q000187:drug effects* / Q000502:physiology*; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy*; D012565:Schizophrenic Psychology
D014150:Antipsychotic Agents