Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.

BACKGROUND AND PURPOSE: Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present stud...

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Main Authors: van Wel, J, Kuypers, K, Theunissen, E, Toennes, S, Spronk, D, Verkes, R, Ramaekers, J
Format: Journal article
Language:English
Published: 2013
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author van Wel, J
Kuypers, K
Theunissen, E
Toennes, S
Spronk, D
Verkes, R
Ramaekers, J
author_facet van Wel, J
Kuypers, K
Theunissen, E
Toennes, S
Spronk, D
Verkes, R
Ramaekers, J
author_sort van Wel, J
collection OXFORD
description BACKGROUND AND PURPOSE: Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present study was designed to assess whether the impairing effects of Δ(9) -tetrahydrocannabinol (THC) in heavy cannabis users would present in a wide range of neuropsychological functions or selectively affect specific performance domains. We also assessed the acute effects of cocaine on neurocognitive functions of heavy cannabis users. EXPERIMENTAL APPROACH: Heavy cannabis users, who had a history of cocaine use (n = 61), participated in a double-blind, placebo-controlled, three-way crossover study. Subjects received single doses of cocaine HCl (300 mg), cannabis (THC μg·kg(-1) ) and placebo, and completed a number of tests measuring impulse control and psychomotor function. KEY RESULTS: Single doses of cannabis impaired psychomotor function and increased response errors during impulsivity tasks. Single doses of cocaine improved psychomotor function and decreased response time in impulsivity tasks, but increased errors. CONCLUSIONS AND IMPLICATIONS: Heavy cannabis users display impairments in a broad range of neuropsychological domains during THC intoxication. Impairments observed in psychomotor tasks, but not in impulsivity tasks, appeared smaller in magnitude as compared with those previously reported in occasional cannabis users. Heavy cannabis users were sensitive to the stimulating and inhibitory effects of cocaine on psychomotor function and impulsivity respectively. The reduction in proficiency in impulse control may put drug users at increased risk of repeated drug use and addiction.
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spelling oxford-uuid:b7676283-ac58-4e7e-b6ae-d9865742998e2022-03-27T04:48:22ZSingle doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b7676283-ac58-4e7e-b6ae-d9865742998eEnglishSymplectic Elements at Oxford2013van Wel, JKuypers, KTheunissen, EToennes, SSpronk, DVerkes, RRamaekers, JBACKGROUND AND PURPOSE: Cannabis is the most popular drug used in the European Union, closely followed by cocaine. Whereas cannabis impairs neurocognitive function in occasional cannabis users, such impairments appear less prominent in heavy users, possibly as a result of tolerance. The present study was designed to assess whether the impairing effects of Δ(9) -tetrahydrocannabinol (THC) in heavy cannabis users would present in a wide range of neuropsychological functions or selectively affect specific performance domains. We also assessed the acute effects of cocaine on neurocognitive functions of heavy cannabis users. EXPERIMENTAL APPROACH: Heavy cannabis users, who had a history of cocaine use (n = 61), participated in a double-blind, placebo-controlled, three-way crossover study. Subjects received single doses of cocaine HCl (300 mg), cannabis (THC μg·kg(-1) ) and placebo, and completed a number of tests measuring impulse control and psychomotor function. KEY RESULTS: Single doses of cannabis impaired psychomotor function and increased response errors during impulsivity tasks. Single doses of cocaine improved psychomotor function and decreased response time in impulsivity tasks, but increased errors. CONCLUSIONS AND IMPLICATIONS: Heavy cannabis users display impairments in a broad range of neuropsychological domains during THC intoxication. Impairments observed in psychomotor tasks, but not in impulsivity tasks, appeared smaller in magnitude as compared with those previously reported in occasional cannabis users. Heavy cannabis users were sensitive to the stimulating and inhibitory effects of cocaine on psychomotor function and impulsivity respectively. The reduction in proficiency in impulse control may put drug users at increased risk of repeated drug use and addiction.
spellingShingle van Wel, J
Kuypers, K
Theunissen, E
Toennes, S
Spronk, D
Verkes, R
Ramaekers, J
Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title_full Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title_fullStr Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title_full_unstemmed Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title_short Single doses of THC and cocaine decrease proficiency of impulse control in heavy cannabis users.
title_sort single doses of thc and cocaine decrease proficiency of impulse control in heavy cannabis users
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