Marijuana is often viewed as a harmless or “natural” substance, particularly among young people. However, research suggests that its use may be associated with certain mental health risks, including psychosis—a condition that affects how a person thinks, feels and perceives reality.
Psychosis is not a disease in itself, but rather a group of symptoms. It may include hallucinations (seeing or hearing things that are not present), delusions (strong beliefs that may not be based in reality), disorganised thinking and changes in behaviour. These symptoms can be distressing for both the individual and their family, and may require medical attention.
Marijuana contains a chemical known as THC (tetrahydrocannabinol), which can affect how the brain processes information. Some studies suggest that THC may interfere with normal brain signalling, particularly in areas related to thinking, memory and perception. In certain individuals, this may contribute to short-term psychotic symptoms. In others—especially those with underlying vulnerability—it may be associated with longer-lasting mental health conditions.
Some groups may face a higher level of risk. These include adolescents and young adults, whose brains are still developing, as well as individuals with a personal or family history of mental health conditions such as schizophrenia. Evidence also indicates that frequent use, early exposure and higher-potency cannabis products may increase the likelihood of experiencing adverse mental health effects.
While some people report using marijuana to cope with stress or anxiety, its effects can vary. In some cases, it may lead to increased anxiety, panic episodes, mood changes or impaired judgement. Where psychotic symptoms occur, medical support may be required.
Another concern is that early signs of mental health difficulties—such as social withdrawal, unusual thoughts, sleep disturbances or behavioural changes—may not always be recognised promptly. Early assessment and appropriate care are generally associated with better outcomes.
Marijuana use is a complex public health issue. Promoting awareness, encouraging informed decision-making and supporting access to mental health services are important steps in safeguarding wellbeing, particularly among young people.
