Skip to main content

Main menu

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN

User menu

Search

  • Advanced search
CMAJ
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN
CMAJ

Advanced Search

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • Visit CMAJ on Facebook
  • Follow CMAJ on Twitter
  • Follow CMAJ on Pinterest
  • Follow CMAJ on Youtube
  • Follow CMAJ on Instagram
Letters

Effects of marijuana on young adults

Maggie Mamen
CMAJ August 06, 2002 167 (3) 233;
Maggie Mamen
Psychologist, Centrepointe Professional Services, Nepean, Ont.
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Responses
  • Metrics
  • PDF
Loading

I was interested to read the article by Peter Fried and colleagues,1 particularly since funding for such long-term, prospective research is increasingly hard to find. The results of this study over the years have been interesting and important. However, I am concerned on 2 counts.

First, it is universally accepted that intelligence is multifaceted. Current research proposes as many as 9 different “intelligences,” including kinesthetic, interpersonal, emotional and motivational, as well as the more traditionally understood verbal and spatial functions. To use IQ difference scores as a dependent variable to measure the effects of anything on the complexity of human cognitive functioning is at best woefully simplistic. At worst, it perpetuates the dangerous and misguided myth that human intelligence can be encapsulated in 1 score — a belief that is abused and misused by many professionals and lay people alike. This “single score” notion not only misrepresents the whole field of modern psychometrics in the area of intellectual assessment but also ignores how marijuana and other drugs may affect some aspects of cognitive functioning but not others. The investigation of any such differential effects would be more challenging, but also far more useful and enlightening.

Second, assuming no error occurred on the table outlining the characteristics of marijuana user groups, the authors chose not to discuss a highly significant result. In the current heavy-user group, prenatal exposure to marijuana was very significantly higher than in all other groups (11.6 joints per week v. 1.4, 1.4 and 1.5 in the non-user, light user and former-user groups, respectively; p < 0.001). This suggests that individuals who were exposed to marijuana in utero are more than 10 times more likely to become heavy users in late adolescence and early adulthood. Surely this is a major finding that should be highlighted and addressed?

Maggie Mamen Psychologist Centrepointe Professional Services Nepean, Ont.

Reference

  1. 1.↵
    Fried P, Watkinson B, James D, Gray R. Current and former marijuana use: preliminary findings of a longitudinal study of effects on IQ in young adults. CMAJ 2002;166(7):887-91.
    OpenUrlAbstract/FREE Full Text
PreviousNext
Back to top

In this issue

CMAJ
Vol. 167, Issue 3
6 Aug 2002
  • Table of Contents
  • Index by author

Article tools

Respond to this article
Print
Download PDF
Article Alerts
To sign up for email alerts or to access your current email alerts, enter your email address below:
Email Article

Thank you for your interest in spreading the word on CMAJ.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Effects of marijuana on young adults
(Your Name) has sent you a message from CMAJ
(Your Name) thought you would like to see the CMAJ web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Effects of marijuana on young adults
Maggie Mamen
CMAJ Aug 2002, 167 (3) 233;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
‍ Request Permissions
Share
Effects of marijuana on young adults
Maggie Mamen
CMAJ Aug 2002, 167 (3) 233;
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like

Jump to section

  • Article
    • Reference
  • Responses
  • Metrics
  • PDF

Related Articles

  • No related articles found.
  • PubMed
  • Google Scholar

Cited By...

  • No citing articles found.
  • Google Scholar

More in this TOC Section

  • An expanded role for blood donor emerging pathogens surveillance
  • Beyond wastewater surveillance: refining environmental pathogen detection in the built environment
  • Observational evidence in support of screening for depression during pregnancy and the postpartum period
Show more Letters

Similar Articles

Collections

  • Topics
    • Addiction medicine
    • Psychiatry & mental health: adult

 

View Latest Classified Ads

Content

  • Current issue
  • Past issues
  • Collections
  • Sections
  • Blog
  • Podcasts
  • Alerts
  • RSS
  • Early releases

Information for

  • Advertisers
  • Authors
  • Reviewers
  • CMA Members
  • CPD credits
  • Media
  • Reprint requests
  • Subscribers

About

  • General Information
  • Journal staff
  • Editorial Board
  • Advisory Panels
  • Governance Council
  • Journal Oversight
  • Careers
  • Contact
  • Copyright and Permissions
  • Accessibiity
  • CMA Civility Standards
CMAJ Group

Copyright 2023, CMA Impact Inc. or its licensors. All rights reserved. ISSN 1488-2329 (e) 0820-3946 (p)

All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association or its subsidiaries.

To receive any of these resources in an accessible format, please contact us at CMAJ Group, 500-1410 Blair Towers Place, Ottawa ON, K1J 9B9; p: 1-888-855-2555; e: cmajgroup@cmaj.ca

Powered by HighWire