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Verbal learning and memory in adolescent cannabis users, alcohol users and non-users

Journal Article


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Abstract


  • Rationale Long-term heavy cannabis use can result in

    memory impairment. Adolescent users may be especially

    vulnerable to the adverse neurocognitive effects of cannabis.

    Objectives and methods In a cross-sectional and prospective

    neuropsychological study of 181 adolescents aged

    16–20 (mean 18.3 years), we compared performance

    indices from one of the most widely used measures of

    learning and memory—the Rey Auditory Verbal Learning

    Test—between cannabis users (n=52; mean 2.4 years of

    use, 14 days/month, median abstinence 20.3 h), alcohol

    users (n=67) and non-user controls (n=62) matched for

    age, education and premorbid intellectual ability (assessed

    prospectively), and alcohol consumption for cannabis and

    alcohol users.

    Results Cannabis users performed significantly worse than

    alcohol users and non-users on all performance indices. They recalled significantly fewer words overall (p<0.001), demonstrating

    impaired learning (p<0.001), retention (p<0.001)

    and retrieval (p<0.05) (Cohen’s d 0.43–0.84). The degree of

    impairment was associated with the duration, quantity,

    frequency and age of onset of cannabis use, but was

    unrelated to alcohol exposure or other drug use. No gender

    effects were detected and the findings remained after

    controlling for premorbid intellectual ability. An earlier age

    of onset of regular cannabis use was associated with worse

    memory performance after controlling for extent of exposure

    to cannabis.

    Conclusions Despite relatively brief exposure, adolescent

    cannabis users relative to their age-matched counterparts

    demonstrated similar memory deficits to those reported in

    adult long-term heavy users. The results indicate that

    cannabis adversely affects the developing brain and

    reinforce concerns regarding the impact of early exposure.

UOW Authors


  •   Solowij, Nadia
  •   Jones, Katy A. (external author)
  •   Rozman, Megan (external author)
  •   Davis, Sasha M. (external author)
  •   Ciarrochi, Joseph (external author)
  •   Heaven, Patrick C. L. (external author)
  •   Lubman, Daniel I. (external author)
  •   Yucel, Murat (external author)

Publication Date


  • 2011

Citation


  • Solowij, N., Jones, K. A., Rozman, M. E., Davis, S. M., Ciarrochi, J. V., Heaven, P. C. L.., Lubman, D. I. & Yucel, M. (2011). Verbal learning and memory in adolescent cannabis users, alcohol users and non-users. Psychopharmacology, 216 (1), 131-144.

Scopus Eid


  • 2-s2.0-79959975886

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2173&context=hbspapers

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/1124

Has Global Citation Frequency


Number Of Pages


  • 13

Start Page


  • 131

End Page


  • 144

Volume


  • 216

Issue


  • 1

Abstract


  • Rationale Long-term heavy cannabis use can result in

    memory impairment. Adolescent users may be especially

    vulnerable to the adverse neurocognitive effects of cannabis.

    Objectives and methods In a cross-sectional and prospective

    neuropsychological study of 181 adolescents aged

    16–20 (mean 18.3 years), we compared performance

    indices from one of the most widely used measures of

    learning and memory—the Rey Auditory Verbal Learning

    Test—between cannabis users (n=52; mean 2.4 years of

    use, 14 days/month, median abstinence 20.3 h), alcohol

    users (n=67) and non-user controls (n=62) matched for

    age, education and premorbid intellectual ability (assessed

    prospectively), and alcohol consumption for cannabis and

    alcohol users.

    Results Cannabis users performed significantly worse than

    alcohol users and non-users on all performance indices. They recalled significantly fewer words overall (p<0.001), demonstrating

    impaired learning (p<0.001), retention (p<0.001)

    and retrieval (p<0.05) (Cohen’s d 0.43–0.84). The degree of

    impairment was associated with the duration, quantity,

    frequency and age of onset of cannabis use, but was

    unrelated to alcohol exposure or other drug use. No gender

    effects were detected and the findings remained after

    controlling for premorbid intellectual ability. An earlier age

    of onset of regular cannabis use was associated with worse

    memory performance after controlling for extent of exposure

    to cannabis.

    Conclusions Despite relatively brief exposure, adolescent

    cannabis users relative to their age-matched counterparts

    demonstrated similar memory deficits to those reported in

    adult long-term heavy users. The results indicate that

    cannabis adversely affects the developing brain and

    reinforce concerns regarding the impact of early exposure.

UOW Authors


  •   Solowij, Nadia
  •   Jones, Katy A. (external author)
  •   Rozman, Megan (external author)
  •   Davis, Sasha M. (external author)
  •   Ciarrochi, Joseph (external author)
  •   Heaven, Patrick C. L. (external author)
  •   Lubman, Daniel I. (external author)
  •   Yucel, Murat (external author)

Publication Date


  • 2011

Citation


  • Solowij, N., Jones, K. A., Rozman, M. E., Davis, S. M., Ciarrochi, J. V., Heaven, P. C. L.., Lubman, D. I. & Yucel, M. (2011). Verbal learning and memory in adolescent cannabis users, alcohol users and non-users. Psychopharmacology, 216 (1), 131-144.

Scopus Eid


  • 2-s2.0-79959975886

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=2173&context=hbspapers

Ro Metadata Url


  • http://ro.uow.edu.au/hbspapers/1124

Has Global Citation Frequency


Number Of Pages


  • 13

Start Page


  • 131

End Page


  • 144

Volume


  • 216

Issue


  • 1