This Article Full Text (OnlineFirst PDF) All Versions of this Article: 0269881108092393v1 0269881108092393v2 0269881108092393v3 23/3/266    most recent Alert me when this article is cited Alert me if a correction is posted 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 Ramaekers, J G Articles by Moeller, M R Search for Related Content PubMed PubMed Citation Articles by Ramaekers, J G Articles by Moeller, M R Social Bookmarking                         What's this?

Neurocognitive performance during acute THC intoxication in heavy and occasional cannabis users

¹ Department of Neuropsychology and Psychopharmacology, Faculty of Psychology, Maastricht University, Maastricht, The Netherlands
² Department of Forensic Toxicology, Institute of Legal Medicine, Goethe University of Frankfurt, Frankfurt, Germany
³ Unikliniken des Saarlandes, Homburg, Germany

^* To whom correspondence should be addressed.

	Abstract

Abstract

Performance impairment during ⁹-tetrahydrocannabinol (THC) intoxication has been well described in occasional cannabis users. It is less clear whether tolerance develops to the impairing effects of THC in heavy users of cannabis. The aim of the present study was to assess neurocognitive performance during acute THC intoxication in occasional and heavy users. Twenty-four subjects (12 occasional cannabis users and 12 heavy cannabis users) participated in a double-blind, placebo-controlled, two-way mixed model design. Both groups received single doses of THC placebo and 500 µg/kg THC by smoking. Performance tests were conducted at regular intervals between 0 and 8 h after smoking, and included measures of perceptual motor control (critical tracking task), dual task processing (divided attention task), motor inhibition (stop signal task) and cognition (Tower of London). THC significantly impaired performance of occasional cannabis users on critical tracking, divided attention and the stop signal task. THC did not affect the performance of heavy cannabis users except in the stop signal task, i.e. stop reaction time increased, particularly at high THC concentrations. Group comparisons of overall performance in occasional and heavy users did not reveal any persistent performance differences due to residual THC in heavy users. These data indicate that cannabis use history strongly determines the behavioural response to single doses of THC.

Key Words: cannabis use history, cognition, impulsivity, performance, THC, tolerance

First published on August 21, 2008, doi:10.1177/0269881108092393

Journal of Psychopharmacology 2009;23:266.

A more recent version of this article appeared on May 1, 2009


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