Cannabis psychosis | what happens and why

Most people who use cannabis will never experience a cannabis psychosis. The risk does rise with heavy use, with stronger products, and where psychosis or schizophrenia runs in your family. An episode can come on within hours, and it can be frightening for you and for the people around you. Knowing the signs makes it easier to tell what you are dealing with.

Psychosis affects how you perceive the world, how you think and how you behave. If you are going through weed psychosis, you may feel frightened or confused, or become convinced that something is happening when there is nothing there. The episode develops during or shortly after cannabis use, and while it lasts you can struggle to tell what is real from what your mind has invented. Your thoughts may also come out jumbled, leaving other people unable to follow you.

Bad trip versus weed psychosis

During a bad trip you may also see, hear or sense things that are not really there. The difference is that you still know the drugs are causing what you see or hear. In a cannabis psychosis that awareness is gone, and all of it is real to you, however impossible it would seem to anyone else. It is also why reassurance from the people around you rarely helps. From where you are standing, they are the ones who have it wrong.

Cannabis psychosis symptoms can come on suddenly, and they vary widely in severity. Common symptoms include:

• paranoia
• hearing voices
• seeing, sensing or smelling things that are not there
• unusual or irrational beliefs
• confusion
• severe anxiety
• agitation
• panic
• disorganised thinking
• suspiciousness
• emotional instability
• difficulty communicating clearly
• difficulty recognising what is real

Some people retain some awareness that something is wrong, while for others everything they think and see feels entirely real. In some cases the episode feels so real that afterwards you are still convinced part of it really happened. That is one of the reasons psychosis is hard to describe once it is over.

Weed-induced psychosis symptoms

Weed-induced psychosis symptoms usually start while you are still intoxicated, or in the hours just after. That timing is one of the clearest signs that cannabis is involved. Symptoms that persist once the cannabis has worn off, or that appear when you have not used for a while, may point to something other than weed-induced psychosis.

Weed psychosis symptoms in others

If you are worried about someone else, the changes you notice are mostly in how they behave:

• unusually fearful behaviour
• social withdrawal
• talking about beliefs that cannot be true
• reacting to things that are not there
• appearing extremely suspicious
• sudden changes in personality
• difficulty following a conversation

If you recognise these cannabis psychosis symptoms in yourself or in someone close to you, you can call us on +27 21 541 0643 for personal advice. The same goes if the effects continue once the cannabis has worn off. Questions from partners and parents are welcome too.

Fatal cannabis overdoses are extremely rare. Taking a large amount at once, especially with high-potency products or edibles, can still leave you severely intoxicated. Weed overdose symptoms include:

• extreme anxiety
• panic attacks
• confusion
• paranoia
• hallucinations
• rapid heart rate
• vomiting
• severe drowsiness
• impaired coordination

That list overlaps heavily with psychosis, and severe intoxication can shade into psychotic symptoms. Telling the two apart from the outside is therefore not always easy.

Cannabis can produce psychotic symptoms such as paranoia and hallucinations while you are under the influence. The European Union Drugs Agency lists psychotic symptoms among the risks of daily use, alongside dependence and chronic breathing problems. 

Whether cannabis causes a lasting psychotic disorder, or unmasks a vulnerability that was already there, remains an open question among researchers. Other substances can trigger an episode too, and with some of them it happens during withdrawal rather than during use. That is what a drug-induced psychosis covers.

Stronger cannabis and higher THC

The strength of what you smoke is part of the picture. According to the European Union Drugs Agency, the average THC content of herbal cannabis in Europe rose by 19% to 12% between 2014 and 2024. Hash rose by 66% over the same period, to 24.6%. A stronger product means a larger dose from the same joint. High-THC cannabis is one of the factors most often associated with psychotic symptoms.

Cannabis does not affect everyone in the same way, and how much you use is only part of it. Factors that can make weed-induced psychosis more likely include:

• using cannabis heavily over a long period
• daily or near-daily use
• starting in your teens
• regular use of high-potency cannabis
• psychosis or schizophrenia in your family
• a previous psychotic episode
• combining cannabis with other drugs

If several of these apply to you, cutting down or stopping can bring that risk back down. And once you have been through an episode, a further one becomes more likely, particularly if you carry on using. One reason is that a first episode can show that you are more prone to psychosis than most people.

How often cannabis-induced psychosis occurs depends on which population you look at, so there is no single figure. For most people it remains an uncommon complication of cannabis use. Among frequent users of high-potency products and among people with a vulnerability to psychotic disorders, it is a good deal more common.

Seriousness of cannabis psychosis symptoms

What matters here is how serious psychosis is, not how often it occurs. The symptoms are worth treating as a medical problem rather than as someone simply being too high. That is as true of a one-off episode as it is of a recurring one.

How long cannabis-induced psychosis lasts varies a great deal from one person to the next. For some people the symptoms start to settle within hours, as the cannabis wears off. For others they continue for days or longer, particularly after heavy use or where there is an underlying mental health condition. Continuing to use cannabis while you recover can prolong it, and it makes a further episode more likely. A psychosis is an intense experience and a serious condition in its own right, and going through one can show that you are more sensitive to it than most people.

An episode like this can leave a mark, and it often raises the question of why the use continued despite what it was doing to you. It is a question worth asking, because the pattern behind the use is what determines what happens next. Going back to cannabis after a psychotic episode, knowing what it cost you, is itself one of the clearest signs of a marijuana addiction.

Treatment and the reasons behind your use

We work with proven therapies and a programme that is tailored to you. That can give you a clearer view of why you use. One reason may be that you often feel down, anxious or tense, and if smoking weed helps you to unwind, it can become the way you deal with those feelings. What causes them does not go away, and cannabis can make them worse over time. We can help you look further than the use itself, and work on the underlying causes with you.

Your programme in South Africa

At our cannabis rehabilitation centre in South Africa you work on the psychological and behavioural patterns that keep the cannabis use in place. Our team is alongside you throughout your stay. Cannabis addiction treatment is evidence-based, and relapse prevention is built in from the start. The average stay is 7 weeks, though a shorter stay can be agreed with you.

If you would like to talk about what happened, or about what a cannabis psychosis means for your use from here, call us on +27 21 541 0643.