Analysis of nearly 3 million treatment episodes in Australia from 2003–2020 found cannabis was consistently the most common principal substance of concern for both adolescents and emerging adults seeking treatment, with treatment completion rates as a key ongoing challenge.
Addiction treatment planners, youth health services, policymakers, and researchers studying substance treatment utilization.
What the researchers found
Cannabis was the most common principal substance of concern for adolescents (ages 10–17) and emerging adults (ages 18–24) across the entire 2003–2020 period. Joinpoint regression revealed trends in treatment settings, planned completion rates, and sex distribution over time.
Why it matters
Despite alcohol being a bigger overall public health problem, cannabis drives more treatment episodes among young Australians than any other substance. Understanding trends in cannabis-related treatment seeking helps health systems plan services for the population that needs them most.
The numbers in context
2,904,012 treatment episodes analyzed. 2003–2020 timeframe. Cannabis: most common principal substance for ages 10–17 and 18–24. Treatment settings, completion, and sex trends examined via joinpoint regression.
How the study worked
Analysis of the Australian Alcohol and Other Drug Treatment Services National Minimum Data Set (N=2,904,012 episodes). Joinpoint regression characterized trends in principal substance, treatment setting, planned completion, and sex among adolescents (10–17), emerging adults (18–24), and adults (25+).
What this study cannot tell us
Administrative treatment data — reflects who seeks treatment, not total population need. Australian-specific context (different cannabis policy than US). Treatment episodes, not individuals (some people appear multiple times). Cannot capture untreated cannabis problems.
How to read the evidence
Large national administrative dataset spanning 18 years with sophisticated trend analysis, providing robust epidemiological evidence.
When this study was published
Published 2025, data from 2003–2020.
The bigger picture
The persistence of cannabis as the top treatment driver for young people despite decades of policy changes and public health campaigns suggests current approaches may be insufficient. Treatment completion rates remain a challenge, indicating a need for youth-specific intervention models.
Questions still open
- Why does cannabis dominate youth treatment despite being viewed as less harmful than alcohol? Are treatment programs designed for adult alcohol users adequate for young cannabis users? Would earlier intervention reduce treatment episodes?
Common questions
Why is cannabis the top reason teens seek treatment?
Are youth cannabis treatment programs effective?
Read the original research
Trends in treatment attendance for substance use disorders among adolescents and emerging adults in Australia, 2003-2020.
Drug and alcohol dependence, 275, 112845
Citation
Wells, Megan; Kelly, Peter J; Larance, Briony. (2025). Trends in treatment attendance for substance use disorders among adolescents and emerging adults in Australia, 2003-2020.. Drug and alcohol dependence, 275, 112845. https://doi.org/10.1016/j.drugalcdep.2025.112845
Explore the wider topic
- How to Talk to Your Teenager About Weed (Without Losing Them)
- My Kid's Friends Smoke Weed: A Parent's Guide
- I Smoke Weed But Don't Want My Kids To: Navigating the Hypocrisy
- Quitting Weed as a Parent: Why It Is the Hardest and Most Important Quit
- Quitting Weed as a Teen or Young Adult
- My Kid Is Smoking Weed: A Parent's Guide