TY - JOUR
T1 - Effects of acute procyclidine administration on prepulse inhibition of the startle response in schizophrenia
T2 - a double-blind, placebo-controlled study
AU - Kumari, Veena
AU - Zachariah, Elizabeth
AU - Galea, Adrian
AU - Jones, Hugh C
AU - Das, Mrigen
AU - Mehrotra, Ravi
AU - Taylor, David
AU - Sharma, Tonmoy
PY - 2003/3
Y1 - 2003/3
N2 - Prepulse inhibition (PPI) of the startle response refers to a reduction in response to a strong stimulus (pulse) if this is preceded shortly by a weak non-startling stimulus (prepulse). Consistent with theories of deficiencies in early stages of information processing, PPI is found to be reduced in patients with schizophrenia. Atypical antipsychotics are found to be more effective than typical antipsychotics in improving PPI in this population. Anticholinergic drugs are often used to control extrapyramidal symptoms induced by antipsychotic medication, especially by typical antipsychotics, in schizophrenic patients and are known to disrupt cognitive functions in both normal and schizophrenic populations. The effect of anticholinergics on PPI in schizophrenia has not yet been examined. This study determined the effects of procyclidine, an anticholinergic drug, on PPI in patients with schizophrenia given risperidone or quetiapine and not on any anticholinergic drugs, employing a placebo-controlled, cross-over design. Under double-blind conditions, subjects were administered oral 15 mg procyclidine and placebo on separate occasions, 2 weeks apart, and tested for acoustic PPI (prepulse 8 dB and 15 dB above the background and delivered with 30-ms, 60-ms and 120-ms prepulse-to-pulse intervals). Procyclidine significantly impaired PPI compared to placebo (assessed as percentage reduction) with 60-ms prepulse-to-pulse trials and increased the latencies to response peak across all trials. The use of anticholinergics needs to be carefully controlled/examined in investigations of information processing deficits using a PPI model and reduced to the minimum level in clinical care of schizophrenia.
AB - Prepulse inhibition (PPI) of the startle response refers to a reduction in response to a strong stimulus (pulse) if this is preceded shortly by a weak non-startling stimulus (prepulse). Consistent with theories of deficiencies in early stages of information processing, PPI is found to be reduced in patients with schizophrenia. Atypical antipsychotics are found to be more effective than typical antipsychotics in improving PPI in this population. Anticholinergic drugs are often used to control extrapyramidal symptoms induced by antipsychotic medication, especially by typical antipsychotics, in schizophrenic patients and are known to disrupt cognitive functions in both normal and schizophrenic populations. The effect of anticholinergics on PPI in schizophrenia has not yet been examined. This study determined the effects of procyclidine, an anticholinergic drug, on PPI in patients with schizophrenia given risperidone or quetiapine and not on any anticholinergic drugs, employing a placebo-controlled, cross-over design. Under double-blind conditions, subjects were administered oral 15 mg procyclidine and placebo on separate occasions, 2 weeks apart, and tested for acoustic PPI (prepulse 8 dB and 15 dB above the background and delivered with 30-ms, 60-ms and 120-ms prepulse-to-pulse intervals). Procyclidine significantly impaired PPI compared to placebo (assessed as percentage reduction) with 60-ms prepulse-to-pulse trials and increased the latencies to response peak across all trials. The use of anticholinergics needs to be carefully controlled/examined in investigations of information processing deficits using a PPI model and reduced to the minimum level in clinical care of schizophrenia.
KW - Acoustic Stimulation
KW - Adult
KW - Affect
KW - Cholinergic Antagonists
KW - Double-Blind Method
KW - Female
KW - Heart Rate
KW - Humans
KW - Inhibition (Psychology)
KW - Male
KW - Middle Aged
KW - Multivariate Analysis
KW - Procyclidine
KW - Reaction Time
KW - Reflex, Startle
KW - Schizophrenic Psychology
UR - http://www.scopus.com/inward/record.url?scp=12244279032&partnerID=8YFLogxK
U2 - 10.1177/0269881103017001710
DO - 10.1177/0269881103017001710
M3 - Article
C2 - 12680744
SN - 0269-8811
VL - 17
SP - 89
EP - 95
JO - Journal of psychopharmacology (Oxford, England)
JF - Journal of psychopharmacology (Oxford, England)
IS - 1
ER -
