Can psilocybin treat opioid addiction? New UK trial aims to find out

Imperial College London's Centre for Psychedelic Research will investigate whether psilocybin therapy can help prevent relapse in people recovering from opioid addiction.

Psilocybin-assisted therapy has already shown promising results in treating alcohol and smoking addictions. Now, researchers hope to see whether the same approach could work for those dependent on opioids such as heroin.

Next year, Imperial College London's Centre for Psychedelic Research will investigate whether psilocybin, when combined with psychological support, can offer a new path for those struggling with opioid addiction.

Funded by the National Institute for Health Research (NIHR) and the UK Government’s Office for Life Sciences, the trial is the first of its kind in the UK — representing a potential breakthrough in addressing opioid use disorder.

The trial is being designed with input from individuals who have experienced opioid addiction firsthand. It will focus on those who have recently undergone detoxification from opioids like heroin, methadone or buprenorphine.

The study will be led by Dr. David Erritzoe, clinical director at the Centre for Psychedelic Research, and Dr. Louise Paterson from the Addiction Research Team at Imperial College London.

Dr. Paterson said: “This trial will examine whether we can improve recovery in a severely under-served group of people – namely, those with opioid dependence during their most vulnerable post-detox phase.

"Clinical studies, including those in our Centre for Psychedelic Research, have shown great promise for this type of treatment in other mental health conditions. We want to see if it works equally well for opioid use disorder.”

The participants will receive psilocybin therapy at the NIHR Clinical Research Facility at Hammersmith Hospital.

Along with therapeutic support, participants will undergo functional MRI brain scans to understand how psilocybin affects the brain’s mechanisms involved in addiction.

Opioid use disorder is a severe global public health issue. The World Health Organization (WHO) estimates that around 600,000 drug-related deaths occurred in 2019 — 80% of which were linked to opioids.

In 2019, the UK had the world’s highest rate of opioid consumption and deaths caused by opiate-related drug poisoning have increased by 388% since 1993 in England and Wales.

Approximately 140,000 people in the UK currently receive treatment for opioid dependence.

However, few treatments effectively prevent relapse after detoxification.

Dr. Erritzoe said: “We know that up to 90% of people relapse back to opioid use within 12 months of finishing detox, so finding new and effective treatments is essential.

"If this trial is successful, it offers hope for a new type of treatment that could make a significant difference to this group of people.”

The study will involve up to six months of post-therapy monitoring to track participants’ opioid use, cravings, mental health outcomes and overall psychological well-being.

Researchers hope this approach will provide new insight into how psychedelics could play a role in long-term recovery from opioid addiction.

The initiative is part of the UK Government’s Addiction Healthcare Goals programme, which aims to create a comprehensive treatment and recovery system for people dealing with drug and alcohol addiction.

Professor Anne Lingford-Hughes, chair of the Addiction Healthcare Goals programme, said: “New approaches to treat drug addiction and reduce drug-related deaths, particularly from overdose, are urgently needed.

"The Addiction Healthcare Goals programme is pleased to fund promising innovations that have brought together partnerships between industry, academia and organisations involved in delivering treatment and care for those experiencing drug addictions.”

If the initial trial yields positive results, the team plans to move forward with larger clinical trials, ultimately aiming to make this treatment available to patients within the NHS.

Recruitment for the trial is expected to begin early next year.

What are opioids and where do they come from?
Opioids are a group of pain-relieving drugs that come from two sources: they're either extracted from the poppy plant (like morphine) or created in laboratories to mimic these natural compounds (like fentanyl). They work by interacting with specific receptors in the brain that manage pain signals.

What drugs are opioids in the UK?
Opioids include morphine, fentanyl, alfentanil, oxycodone, diamorphine, methadone, buprenorphine, hydromorphone and tramadol.

What are opioids commonly used for?
Healthcare providers primarily prescribe opioids to treat various types of pain. Common prescription opioids include morphine (typically for severe pain), fentanyl (often used in cancer treatment) and tramadol (prescribed for moderate to severe pain).

What makes opioids potentially dangerous?
Opioids can be dangerous because they affect your breathing rate. During an overdose, they can slow or stop breathing entirely, which can be fatal. This risk increases with non-medical use, prolonged use or use without proper medical supervision.

What are the risks of using opioids?
Using opioids without medical supervision can lead to several serious problems including development of opioid dependence, increased risk of overdose, breathing difficulties and potential fatal complications.

How many people who need treatment for opioid dependence actually receive it?
Despite the existence of effective treatments for opioid dependence, less than 10% of people who need treatment currently receive it. This represents a significant global healthcare gap that needs addressing.

Can psychedelics treat opioid addiction?
Early clinical research is underway to examine if psilocybin therapy can treat opioid use disorder. These studies are taking place across the UK, Europe, Canada and the US at universities and pharmaceutical companies. A 2022 study found that recent psychedelic use was associated with 55% reduced likelihood of subsequent daily opioid use. A 2024 study demonstrated that psilocybin reduces heroin seeking behaviours in rats. Johns Hopkins Center for Psychedelic and Consciousness Research is currently recruiting applicants for a trial on psilocybin for opioid addiction. For a summary of the past, present and future of research investigating psychedelic therapies for addiction, click here.

Feature image: mattbuck / Wikimedia Commons