Cognition and cannabis use behaviour

Background

With prevalence of recent illicit cannabis use at 11.5%, Australia has one of the highest rates of cannabis use in the world. Among Priority Populations, illicit use is particularly high. Australians 18-24 yrs are more likely to use cannabis than any other age group, with 25.5% reporting recent use, and among those aged 14-17 yrs, prevalence is at 9.7%. LGBTIQ+ youth report prevalence at 28.3%. Adolescents are more likely than any other age group to have engaged in high-risk cannabis use. Regular use is associated with low educational attainment, greater risk of developing or exacerbating mental health conditions, social problems, cognitive impairment (particularly executive dysfunction), poor work productivity, reduced quality of life, and higher risk of motor accidents. Use during younger years has been linked to changes in brain structure and function as well as reduced IQ, all of which persist beyond acute intoxication.

Our own research shows earlier age of onset is associated with worse cognitive outcomes. The most common adverse effect of chronic use is Cannabis Use Disorder (CUD). Australia has some of the highest rates of CUD and cannabis-related disability in the world. CUD onset most commonly occurs during adolescence or young adulthood: one in six adolescents who try cannabis will develop CUD. Further, rates of CUD among those using cannabis for medicinal purposes (25%) are comparable to those reporting recreational use. While 17% of persons seeking drug treatment in Australia cite cannabis as their principal drug of concern, it is listed as the primary drug of concern by 64% of 10-19-yr-olds and 30% of 20-29-yr-olds in treatment. CUD accounts for 23.5 per 100,000 disability-adjusted life years. This burden is disproportionally shouldered by people under 25 years. In 2020, the economic and social cost of cannabis use in Australia was estimated at $4.5 billion. Reducing cannabis use by young people, including LGBTIQ+ youth, will reduce the harm caused by cannabis in this population. Reduction will minimise pain and suffering at the individual level and assist in alleviating the health and economic burden related to consequences of cannabis use.

Research Questions / Hypotheses

This study forms part of a preliminary survey of a representative sample of young (including LGBTIQ+) people to chart typical form (buds, hashish, oil, etc.) and method (joint, bong, vaporizer, etc.) of medicinal and illicit cannabis use.

Participants

Data collection is ongoing. Nonetheless, 247 participants registered for the study in S2 2025. Around 100 of these were excluded as they did not use cannabis.

Methods

Data will contribute to a brief commentary on current form/method of cannabis use among young (including LGBTIQ+) Australians

Results

Data collection is ongoing. We expect this will be an epidemiological analysis.

Implications

This study will be the first stage of a larger project that aims to reduce cannabis use and harm among young Australians.