This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Contact me when this article is cited  Related Content  • Similar articles in JAMA  Social Bookmarking   What's this?

Harrison G. Pope, Jr, MD; Deborah Yurgelun-Todd, PhD

JAMA. 1996;275(7):521-527.

Abstract
Objective.
—To assess whether frequent marijuana use is associated with residual neuropsychological effects.

Design.
—Single-blind comparison of regular users vs infrequent users of marijuana.

Participants.
—Two samples of college undergraduates: 65 heavy users, who had smoked marijuana a median of 29 days in the past 30 days (range, 22 to 30 days) and who also displayed cannabinoids in their urine, and 64 light users, who had smoked a median of 1 day in the last 30 days (range, 0 to 9 days) and who displayed no urinary cannabinoids.

Intervention.
—Subjects arrived at 2 PM on day 1 of their study visit, then remained at our center overnight under supervision. Neuropsychological tests were administered to all subjects starting at 9 AM on day 2. Thus, all subjects were abstinent from marijuana and other drugs for a minimum of 19 hours before testing.

Main Outcome Measures.
—Subjects received a battery of standard neuropsychological tests to assess general intellectual functioning, abstraction ability, sustained attention, verbal fluency, and ability to learn and recall new verbal and visuospatial information.

Results.
—Heavy users displayed significantly greater impairment than light users on attentional/executive functions, as evidenced particularly by greater perseverations on card sorting and reduced learning of word lists. These differences remained after controlling for potential confounding variables, such as estimated levels of premorbid cognitive functioning, and for use of alcohol and other substances in the two groups.

Conclusions.
—Heavy marijuana use is associated with residual neuropsychological effects even after a day of supervised abstinence from the drug. However, the question remains open as to whether this impairment is due to a residue of drug in the brain, a withdrawal effect from the drug, or a frank neurotoxic effect of the drug.

(JAMA. 1996;275:521-527)

Author Affiliations
From the Biological Psychiatry Laboratory (Dr Pope) and the Brain Imaging Center (Dr Yurgelun-Todd), McLean Hospital, Belmont, Mass, and Department of Psychiatry, Harvard Medical School, Boston, Mass (Drs Pope and Yurgelun-Todd).

Footnotes
Reprint requests to Biological Psychiatry Laboratory, McLean Hospital, 115 Mill St, Belmont, MA 02178 (Dr Pope).

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

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Regional Brain Abnormalities Associated With Long-term Heavy Cannabis Use
Yucel et al.
Arch Gen Psychiatry 2008;65:694-701.
ABSTRACT | FULL TEXT  

The Role of Schools in Combating Illicit Substance Abuse
Council on School Health and Committee on Substanc
Pediatrics 2007;120:1379-1384.
ABSTRACT | FULL TEXT  

Symptoms of ADHD or Marijuana Use?
GRAHAM et al.
Am. J. Psychiatry 2007;164:973-973.
FULL TEXT  

Opposing actions of chronic {Delta}9-tetrahydrocannabinol and cannabinoid antagonists on hippocampal long-term potentiation
Hoffman et al.
Learn. Mem. 2007;14:63-74.
ABSTRACT | FULL TEXT  

Repeated cannabinoid exposure during perinatal, adolescent or early adult ages produces similar longlasting deficits in object recognition and reduced social interaction in rats
O'Shea et al.
J Psychopharmacol 2006;20:611-621.
ABSTRACT  

Brain Neuroimaging in Cannabis Use: A Review
Quickfall and Crockford
J. Neuropsychiatry Clin. Neurosi. 2006;18:318-332.
ABSTRACT | FULL TEXT  

Marijuana use is associated with a reorganized visual-attention network and cerebellar hypoactivation
Chang et al.
Brain 2006;129:1096-1112.
ABSTRACT | FULL TEXT  

A community based investigation of the association between cannabis use, injuries and accidents
Wadsworth et al.
J Psychopharmacol 2006;20:5-13.
ABSTRACT  

Cannabis use, cognitive performance and mood in a sample of workers
Wadsworth et al.
J Psychopharmacol 2006;20:14-23.
ABSTRACT  

Chronic cannabinoid exposure produces lasting memory impairment and increased anxiety in adolescent but not adult rats
O'Shea et al.
J Psychopharmacol 2004;18:502-508.
ABSTRACT  

The social distribution of reports of health-related concerns among adolescents in Sao Paulo, Brazil
de Moura
Health Educ Res 2004;19:175-184.
ABSTRACT | FULL TEXT  

Survey of cannabis use in patients with amyotrophic lateral sclerosis
Amtmann et al.
AM J HOSP PALLIAT CARE 2004;21:95-104.
ABSTRACT  

Is ADHD a Risk Factor for Psychoactive Substance Use Disorders? Finding From a Four-Year Prospective Follow-Up Study
Biederman et al.
Focus 2003;1:196-204.
ABSTRACT | FULL TEXT  

Dose-related neurocognitive effects of marijuana use
Bolla et al.
Neurology 2002;59:1337-1343.
ABSTRACT | FULL TEXT  

Does Marijuana Use Cause Long-term Cognitive Deficits?
Gunderson et al.
JAMA 2002;287:2652-2654.
FULL TEXT  

Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults
Fried et al.
CMAJ 2002;166:887-891.
ABSTRACT | FULL TEXT  

Cognitive Functioning of Long-term Heavy Cannabis Users Seeking Treatment
Solowij et al.
JAMA 2002;287:1123-1131.
ABSTRACT | FULL TEXT  

Cannabis, Cognition, and Residual Confounding
Pope
JAMA 2002;287:1172-1174.
FULL TEXT  

Neuropsychological Performance in Long-term Cannabis Users
Pope et al.
Arch Gen Psychiatry 2001;58:909-915.
ABSTRACT | FULL TEXT  

Marijuana Abstinence Effects in Marijuana Smokers Maintained in Their Home Environment
Budney et al.
Arch Gen Psychiatry 2001;58:917-924.
ABSTRACT | FULL TEXT  

Marijuana in the management of amyotrophic lateral sclerosis
Carter and Rosen
AM J HOSP PALLIAT CARE 2001;18:264-270.
ABSTRACT  

Cannabinoids Reveal the Necessity of Hippocampal Neural Encoding for Short-Term Memory in Rats
Hampson and Deadwyler
J. Neurosci. 2000;20:8932-8942.
ABSTRACT | FULL TEXT  

Neurobehavioural consequences of substance abuse and HIV infection
Basso and Bornstein
J Psychopharmacol 2000;14:228-237.
ABSTRACT  

Marijuana: A Continuing Concern for Pediatricians
Committee on Substance Abuse
Pediatrics 1999;104:982-985.
ABSTRACT | FULL TEXT  

Marijuana Smoking vs Cannabinoids for Glaucoma Therapy
Green
Arch Ophthalmol 1998;116:1433-1437.
ABSTRACT | FULL TEXT  

Adolescents and Illicit Drug Use
Bruner and Fishman
JAMA 1998;280:597-598.
FULL TEXT  

Hippocampal Neurotoxicity of Delta 9-Tetrahydrocannabinol
Chan et al.
J. Neurosci. 1998;18:5322-5332.
ABSTRACT | FULL TEXT  

Medicinal Applications of Delta-9-Tetrahydrocannabinol and Marijuana
Voth and Schwartz
ANN INTERN MED 1997;126:791-798.
ABSTRACT | FULL TEXT  

Cognitive Effects of Marijuana
Scheier and Botvin
JAMA 1996;275:1547-1547.
ABSTRACT  

Marijuana's Cognitive Effects Persist
JWatch Psychiatry 1996;1996:16-16.
FULL TEXT  

MARIJUANA'S COGNITIVE EFFECTS PERSIST
JWatch General 1996;1996:4-4.
FULL TEXT  

Does Heavy Marijuana Use Impair Human Cognition and Brain Function?
Block
JAMA 1996;275:560-561.
ABSTRACT