Cannabis & mental health

THC is intoxicating. It can temporarily change mood, thoughts and how you see and hear things.

Higher amounts of THC have stronger effects on the brain and raise the chance of taking too much.

CBD is not intoxicating like THC. The CDC says scientists are still learning how CBD affects the body.

THC in seized cannabis rose from 3.96% in 1995 to 16.14% in 2022. Flower and concentrates sold in dispensaries can have more than 40% THC.

Stronger products are linked to more anxiety and panic, and to a higher risk of psychosis with daily use.

The CDC says it can take up to 2 hours to feel the effects of edibles and drinks. People sometimes take more because they think the first dose isn’t working.

Taking too much feels like the usual effects, but stronger. Serious reactions can lead to injuries like falls or crashes.

The CDC says cannabis can cause disorientation and sometimes unpleasant thoughts or feelings of anxiety and paranoia.

The CDC says cannabis use is associated with depression and social anxiety. NIDA notes that some research shows a higher risk of depression in people who use cannabis as teens.

Research has also linked cannabis use to thoughts of suicide and suicide attempts.

When people stop after heavy or long-term use, they can feel irritable, anxious, low or unable to sleep. That can feel like the original problem coming back, and make it hard to stop.

NIDA says more research is needed to know whether cannabis causes or adds to poor mental health. Genetics, trauma and stress affect both mental health and drug use.

The CDC says the link between cannabis and schizophrenia is stronger in people who start using at a younger age and who use more often.

A study across 11 sites in Europe and Brazil found that people who used cannabis daily had about 3 times the odds of a psychotic disorder. For daily use of high-potency cannabis, it was nearly 5 times.

Studies like this show a strong link, but they cannot prove cause and effect on their own.

A study of health records from 6.9 million people in Denmark estimated that up to 30% of schizophrenia cases in men aged 21 to 30 might have been prevented by avoiding cannabis use disorder. For women aged 16 to 49, the estimate was 4%.

NIDA says some evidence links cannabis use to earlier psychosis in people with genetic risk factors.

NIDA says regular, heavy use in adolescence is linked to effects on working memory, processing speed, verbal memory and school performance. It is also linked to lower education, employment and income in young adulthood.

The CDC lists effects such as:

• Difficulty keeping attention
• Problems with memory and learning
• Problems with thinking and problem-solving

The CDC says cannabis use has been linked to mental health problems such as depression and social anxiety. Earlier and more frequent use is tied to a stronger link with schizophrenia.

Risk of cannabis use disorder is higher for people who start during youth or adolescence and for those who use often.

Cannabis can slow reaction time and weaken coordination and focus, all of which are needed to drive safely.

• Starting during youth or adolescence
• Using more often, especially daily
• Using stronger, higher-THC products

Some people find they need more cannabis, or stronger cannabis, over time to feel the same effect.

After stopping or cutting down heavy or long-term use, people may feel angry, irritable, nervous, anxious, low or restless, and have trouble sleeping or headaches. About 12% of people who use cannabis often have withdrawal.

Cannabinoid hyperemesis syndrome causes nausea, vomiting and stomach pain after long-term, heavy cannabis use. Symptoms go away only when a person stops using cannabis completely.

NIDA names these approaches:

• Cognitive behavioral therapy (learning to spot and change patterns)
• Contingency management (rewards for reaching goals)
• Motivational enhancement therapy (building your own reasons for change)

The CDC says using cannabis while pregnant or breastfeeding may harm the baby, and advises people who are breastfeeding to avoid it.

The CDC says secondhand cannabis smoke contains many of the same toxic and cancer-causing chemicals found in tobacco smoke.

If you’ve been using heavily, the first days may bring irritability, anxiety or poor sleep. These withdrawal feelings are temporary.

• Describe what you’ve noticed, without labels
• Ask how they’re doing, and really listen
• Say why you care, using “I” statements
• Offer to help them find information or support

Because cannabis is linked to psychosis, take sudden changes seriously, like hearing voices, deep suspicion or confused thinking.

SAMHSA’s National Helpline (1-800-662-4357) serves family members as well as people who use substances. It is free, confidential and open 24/7.

Cannabis use disorder is common, and the risk is higher for people who start young and use daily.

Anxiety, fear and panic are more common with large amounts and strong products. Anxiety is also a common withdrawal symptom.

Frequent heavy use is linked to problems with learning and memory, and long-term heavy use can cause cannabinoid hyperemesis syndrome.

THC in seized cannabis rose from about 4% to about 16% between 1995 and 2022, and some products are much stronger.

CBD is not intoxicating like THC, and scientists are still learning how it affects the body.