Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul;27(6):621-636.
doi: 10.1017/S1355617721000631.

Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance

Nirvi Ajmera  1 , Paul F Collins  1 , Hannah Weiss  1 , Monica Luciana  1
Affiliations

Initiation of Moderately Frequent Cannabis use in Adolescence and Young Adulthood is Associated with Declines in Verbal Learning and Memory: A Longitudinal Comparison of Pre- versus Post-Initiation Cognitive Performance

Nirvi Ajmera et al. J Int Neuropsychol Soc. 2021 Jul.

Abstract

Objective: Cannabis use is associated with relative cognitive weaknesses as observed by cross-sectional as well as longitudinal research. Longitudinal studies, controlling for relevant confounds, are necessary to differentiate premorbid from post-initiation contributions to these effects.

Methods: We followed a sample of adolescents and young adults across ten years. Participants provided neurocognitive data and substance use information at two-year intervals. Participants who initiated cannabis and/or alcohol use were identified (n = 86) and split into alcohol-only initiators (n = 39) and infrequent (n = 29) and moderately frequent (n = 18) cannabis initiators. Participants completed the Rey Auditory Verbal Learning Task (RAVLT) and the Iowa Gambling Task (IGT). Group differences before and after substance use initiation and the extent to which alcohol, nicotine, and cannabis use frequencies contributed to cognitive functions over time were examined.

Results: After controlling for parental education, RAVLT new learning was worse in moderately frequent cannabis users prior to use initiation. RAVLT total learning and delayed recall showed significant declines from pre- to post-initiation in moderately frequent cannabis users. Regression analyses confirmed that frequencies of cannabis, but not alcohol, use contributed to post-initiation variations. Nicotine use showed an independent negative association with delayed memory. Findings for the IGT were not significant.

Conclusions: Verbal learning and memory may be disrupted following the initiation of moderately frequent cannabis use while decreased new learning may represent a premorbid liability. Our use of a control group of alcohol-only users adds interpretive clarity to the findings and suggests that future studies should carefully control for comorbid substance use.

Keywords: Adolescence; Cannabis; Decision-making; Substance use; Verbal memory; Working memory.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Pre-initiation RAVLT new learning scores were calculated by averaging the total raw correct responses to trial 1 and List B. Values represent estimated marginal means +/− the 95% confidence interval. As indicated, there was a main effect of group on performance with worse performance in the moderately frequent cannabis users relative to alcohol-only users (p=.039) and infrequent cannabis users (p=.045).
Figure 2.
Figure 2.
Differences between pre-initiation and post-initiation RAVLT 30-minute delayed recall scores are presented for each group, controlling for parental education and pre-initiation performance. Values are estimated marginal means +/− the 95% confidence interval. Positive scores reflect increases over time; negative scores reflect decreases over time. Those who initiated moderately frequent use of cannabis showed declines in performance from pre-to-post initiation relative to less frequent users of cannabis (p=.011).
See this image and copyright information in PMC

References

    1. Achenbach TM, Rescorla LA. (2001). Manual for the ASEBA School-Age Forms & Profiles. Burlington, VT: University of Vermont, Research Center for Children, Youth, & Families.
    1. Achenbach TM, Rescorla LA. (2003). Manual for the ASEBA adult forms & profiles. Research Center for Children, Youth, & Families, University of Vermont, Burlington, VT, USA.
    1. Almy B, Kuskowski M, Malone S, Myers E, Luciana M (2018). A longitudinal analysis of adolescent decision-making with the Iowa Gambling Task. Developmental Psychology, 54(4), 689–702. - PMC - PubMed
    1. American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders: DSM-IV-TR. Washington, DC: American Psychiatric Association.
    1. Barthelemy OJ, Richardson MA, Heeren TC, Chen CA, Liebschutz JM, Forman LS, … & Rose-Jacobs R (2019). Do differences in learning performance precede or follow initiation of marijuana use?. Journal of Studies on Alcohol and Drugs, 80(1), 5–14. doi:10.15288/jsad.2019.80.5. - DOI - PMC - PubMed

Publication types