Cannabis and the developing brain

THC, the main active ingredient in cannabis, binds to receptors in the brain. Regular use while the brain is still developing can have lasting effects.

Memory, learning and attention

Regular cannabis use can affect memory, learning, attention, problem solving, impulse control and how well young people manage stress.

Mental health

Young people who use cannabis have a higher risk of developing psychosis or schizophrenia later in life. Regular use may also make anxiety or depression worse over time.

School and dependence

People who start using cannabis in adolescence are more likely to leave school early and to develop dependence.

Why age and frequency matter

The risk of harm goes up the younger someone starts, the more they use and the more often they use. Not using cannabis is the most effective way to avoid these risks. For young people who do use it, delaying use and using less lower the risk.

Help young people delay first use

The Supporting teenagers toolkit shows how communities can strengthen the protective factors that help young people avoid or delay alcohol and other drug use.

Support parents and carers

Parents and carers have a big influence on young people. See how to help parents talk to teens about alcohol and other drugs and the Parenting toolkit.

Work with local schools

Schools are one of the best places to reach young people. Read what works in alcohol and other drug education in schools.

Reach young adults

The Alcohol, other drugs and young adults toolkit covers prevention for people aged 18 to 24.

• Cannabis (THC) drug facts (Alcohol and Drug Foundation)
• The Growing Brain community toolkit (Mental Health Commission WA, PDF, 2022)
• Positive Choices (evidence-based AOD education resources for schools and families)

Last reviewed: 14 October 2026