A leading consultant psychiatrist at Priory has warned that cannabis induced psychosis has become increasingly common across the UK due to easy online access to highly potent ‘skunk’.
- Users are underestimating risks of cannabis use, says expert
- Super strength ‘skunk’ easily accessible online
- Consequences last a lifetime, even if a user stops taking cannabis
- Priory shares five cannabis addiction warning signs
Dr Niall Campbell, a Priory consultant psychiatrist specialising in addictions, has observed a deepening public health issue - with catastrophic lifelong consequences for users.
“There has been a visible rise in the number of people needing intensive support for psychosis as a result of cannabis use,” he said: “I don’t think this rise is that surprising given how easy skunk is to buy online, and how ubiquitous it has become.”
Cannabis, also known as marijuana or weed, is a widely used drug that can lead to dependency with heavy use. In the year to March 2024, 2.3 million people in the UK reported using cannabis.
Skunk is made from unpollinated cannabis plants which naturally contain higher levels of THC, which creates a stronger effect for the user and greatly increases the likelihood of subsequent paranoia and hallucinations.
A report released earlier this year by the London Drugs Commission called for more services focused on cannabis addiction, improved education for both young people and healthcare professionals, and the removal of cannabis as a Class B drug from the Misuse of Drugs Act.
Dr Campbell, who supports patients at Priory Hospital Roehampton in London, said: “Cannabis addiction is a growing concern, with many people underestimating its potential to lead to dependency.
“What begins with people smoking a few ‘joints’ and feeling a bit paranoid can easily escalate. Over time people can reach a psychotic state which won’t go away, even if they stop smoking.
“Sadly, this psychosis may last a lifetime.
“On top of this, other aspects of people’s mental health can deteriorate once they are given a diagnosis like this. People can become very depressed or suicidal.”
The five key signs you might be addicted to cannabis
Cannabis addiction symptoms can be physical, psychological and behavioural/social, and could include:
- Using cannabis to cope with stress or emotions, or prioritising it over responsibilities
- Using cannabis frequently despite harmful consequences
- Developing a tolerance to cannabis or experiencing withdrawal symptoms when you’re not taking it
- Changes in appetite, disrupted sleep patterns or fatigue
- Increased anxiety, paranoia or lack of motivation
In July 2025, Priory - the UK’s largest independent provider of mental health, addiction and adult social care services – relaunched its long-running addiction treatment programme to increase accessibility for people in need of support. The new addiction services were created in response to rising rates of addiction across the UK including increased harm from alcohol, gambling, ketamine and cocaine misuse.