ORCID

Abstract

RationaleCannabis use disorder (CUD) is highly prevalent with ∼44 million cases worldwide. CUD has been associated with compulsive use despite experiencing adverse psychosocial outcomes. Such adverse outcomes of CUD have been attributed to altered cognition - a set of mental processes that support the organisation and implementation of goal-directed behaviour. However, the evidence is mixed and limited by methodological issues including inconsistent assessment of CUD and metrics of cannabis use.Objective/MethodsThis study examined distinct domains of cognition (i.e., executive function, working memory, episodic memory, verbal reasoning, attention, IQ) in 115 participants aged 18.5 to 32.5 years. We compared performance between 83 participants who endorsed a CUD and 32 controls. We also explored whether the level of problematic cannabis use, and cannabis grams/past month was associated with cognition in CUD. All analyses accounted for alcohol/nicotine use and trait anxiety.ResultsCUD compared to control participants showed significantly lower IQ, with a strong effect size (p < .001, d = 0.862), which was driven by lower verbal IQ, and survived adjusting for education years. There were no other significant effects of group or associations between cognition, level of problematic cannabis use, or dosage.ConclusionsAltered cognition in young adults who endorse a CUD may be specific to verbal IQ. Future work is required to confirm whether these findings generalise to CUD samples across the lifespan, including the most vulnerable individuals with a CUD who are seeking or receiving treatment and that endorse comorbid psychopathologies.

Publication Date

2025-07-10

Publication Title

Comprehensive Psychiatry

Volume

142

ISSN

0010-440X

Deposit Date

2026-08-24

Funding

The present study was nested within a larger investigation titled ‘Characterising neurobiological abnormalities in Cannabis Use Disorders’ funded by the National Health and Medical Research Council Project Grant Scheme (NHMRC ID:1130079). Ms. Gabrielle Abbott did not receive funding support from any organisation for the submitted work. Dr. Lisa-Marie Greenwood did not receive funding support from any organisation for the submitted work. Dr. Jessica Bartschi did not receive funding support from any organisation for the submitted work. Dr. Suraya Dunsford did not receive funding support from any organisation for the submitted work. Dr. Gary Chan was supported by a NHMRC Investigator Grant (GNT1176137). Honorary Professor Nadia Solowij did not receive funding support from any organisation for the submitted work. Dr. Antonio Verdejo-Garcia was supported by an NHMRC Investigator Leadership Grant (2009464). Dr. Janna Cousijn did not receive funding support from any organisation for the submitted work. Ms. Marianna Quinones Valera was funded by Australian Government Research Training Program (RTP) Stipend scholarships. The work within the Neuroscience of Addition and Mental Health Program, Healthy Brain and Mind Research Centre was supported via an ACU competitive scheme. Professor Valentina Lorenzetti was supported by an Al and Val Rosenstrauss Research Fellowship (2022–2026), and by a National Health & Medical Research Council (NHMRC) Investigator Grant (2023–2027, ID 2016833) and an Australian Catholic University competitive scheme.

Keywords

Cannabis, Cannabis use disorder, Cognition, Dosage, IQ, Intelligence quotient

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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