This Article Full Text (PDF) All Versions of this Article: 0269881105057516v1 20/4/471    most recent References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Kedzior, K. K. Articles by Martin-Iverson, M. T. Search for Related Content PubMed PubMed Citation Articles by Kedzior, K. K. Articles by Martin-Iverson, M. T. Social Bookmarking                         What's this?

Chronic cannabis use is associated with attention-modulated reduction in prepulse inhibition of the startle reflex in healthy humans

Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Mt Claremont WA 6190, Australia; School of Medicine and Pharmacology, Faculty of Medicine and Dentistry, University of Western Australia, Crawley WA 6009, Australia

Mathew T. Martin-Iverson

School of Medicine and Pharmacology, Faculty of Medicine and Dentistry, University of Western Australia, Crawley WA 6009, Australia; Centre for Clinical Research in Neuropsychiatry, Graylands Hospital, Mt Claremont WA 6190, Australia

Regardless of a wide research interest the nature of a relationship between cannabis use and schizophrenia is controversial. One of the physiological abnormalities in schizophrenia is attention-modulated deficit in prepulse inhibition (PPI), which is a normal reduction in the startle reflex magnitude when a non-startling stimulus (prepulse) precedes the startling stimulus (pulse). This experiment was designed to determine whether or not otherwise healthy people using cannabis would exhibit attention-modulated deficit in PPI. The startle reflex was recorded in carefully screened healthy humans attending to and ignoring auditory pulse and prepulse stimuli separated by short (20-200 ms) and long prepulse intervals (1600 ms). In contrast to 12 non-using controls, cannabis use in 16 healthy humans was associated with significant reduction in%PPI while attending to auditory stimuli, but not while ignoring them. The PPI was correlated with the duration of cannabis use but not with the concentration of cannabinoid metabolites in urine and the recency of cannabis use in the preceding 24 hours. Cannabis use was not associated with changes in prepulse facilitation of startle reflex magnitude (%PPF) at long prepulse intervals, prepulse facilitation of startle reflex latency and startle reflex magnitude in the absence of prepulses. These results suggest that chronic, but not acute, use of cannabis is associated with schizophrenia-like disruption in PPI in healthy controls. Such reduction in PPI is attention-dependent and does not reflect a global deficit in sensorimotor gating in cannabis users.

Key Words: cannabis use • attention • prepulse inhibition • startle reflex • human

This version was published on July 1, 2006

Journal of Psychopharmacology, Vol. 20, No. 4, 471-484 (2006)
DOI: 10.1177/0269881105057516


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?