Cannabis: Health Effects, Risks and Getting Help to Cut Down

Cannabis laws are changing in many countries, but its effects on the body and brain haven’t. Many people use it without serious problems. For others, especially teenagers and regular users of high-strength products, the risks are real.

Imagine a 19-year-old who started smoking cannabis to relax. Now it’s daily. He feels flat without it, his sleep is a mess, he’s dropped out of college, and lately he’s felt paranoid that people are watching him. He thought cannabis was harmless because it’s “natural.”

Possible health effects

• Mental health: anxiety, paranoia, and a higher risk of psychosis, especially with high-THC products, frequent use and use starting in adolescence
• Memory and concentration problems
• Dependence: some regular users develop cannabis use disorder
• Lungs: smoking can cause coughing and bronchitis
• Cannabinoid hyperemesis syndrome: repeated severe vomiting in some long-term users
• Driving: impaired reaction times
• Pregnancy: not recommended, as it may affect the baby

But what about medical cannabis?

Some prescribed cannabis-based medicines have evidence for specific conditions, such as certain severe epilepsies and multiple sclerosis spasticity. That’s different from recreational use, and products bought online may not contain what they claim.

Getting help

Signs you may need support include using more than you intended, failing to cut down, and continuing despite problems. A doctor, nurse or local drug and alcohol service can help without judgement. Cutting down gradually can ease withdrawal symptoms such as irritability and poor sleep.

Sources: World Health Organization (Cannabis), US Centers for Disease Control and Prevention (Cannabis and health), NHS (Cannabis: the facts). This guide is for general information and does not replace advice from your own nurse, doctor or drug and alcohol service.