Meet the people and compounds behind the startling therapeutic promise of psychedelics.

People are suffering.

Recent polls suggest that 13% of Americans felt depressed in the 2 weeks prior to being asked, while 46% of EU citizens felt depressed or anxious in the last 12 months. If those figures are correct on a population level, then hundreds of millions of people are currently struggling with their mental health.

It’s been decades since we came up with new treatments for these pervasive conditions. The ones we have can bring unwanted effects. For some people, existing treatments don’t work at all.

Psychedelic-Assisted Therapy (PAT) offers a new approach. Its 50-60% early success rates are remarkably high. This is a different kind of treatment, where patients explore underlying trauma in intensive therapeutic sessions – but do not need daily medication.

PAT is now providing hope for treating conditions we currently have limited options for, like treatment-resistant depression, severe post traumatic stress disorder (PTSD), anorexia or substance use disorders.

Researchers are coming together to explore this early promise: determining which therapies and compounds work best for different conditions, and unpicking the biological mechanisms behind their profound effects.

To understand the psychedelic research frontier, let’s zoom in on the Cambridge Psychedelic Research Group (CPRG).

Altered states

Here is Dr Liliana Galindo (Lili). She is Colombian born, softly spoken, and infinitely curious.

Lili is an Affiliated Assistant Professor in the Department of Psychiatry and Principal Investigator of the CPRG. She splits her time between medical research and her clinical role as a Consultant Psychiatrist for the local NHS trust.

“I’ve always been fascinated by our mind’s capability to generate altered states,” says Lili. “Minds allow us to perceive the world, to be creative and to dream. But they can also create nightmares and distortions of reality.”

Lili started to study psychoactive substances, including psychedelics, in Spain. When she arrived in Cambridge in 2018, she was interested in how psychedelics might help us overcome mental challenges. But to start answering these questions, she needed a team.

Testing the safety and efficacy of psychedelic substances is a big operation. You need therapists, medics, psychiatrists, pharmacists, nurses and clinical research practitioners.

Lili helped gather these experts into what became the CPRG, a three-way partnership between the University, the Cambridgeshire and Peterborough NHS Foundation Trust and Cambridge University Hospitals NHS Foundation Trust.

After obtaining their Home Office license to study psychoactive substances in 2023, the group set up their first trial for PTSD.

Since then, the group has moved to develop a wide range of trials. This year will see the group trialling psilocybin-assisted therapy for generalised anxiety disorder and treatment-resistant depression.

Also currently in development is a study for MDMA-assisted group therapy for veterans, first responders and war correspondents suffering with PTSD in the UK. This trial is a partnership with the charity Supporting Wounded Veterans, who are funding the research. Early results in similar trials suggest that around 60% of PTSD sufferers no longer met the criteria for PTSD after treatment.

Across all the trials so far, Lili’s group reports that the treatments are well tolerated, with no risks or reports of substance misuse afterwards.

The clinical approach appears to be working. But how are these treatments so powerful, and what do they involve?

It’s time to meet the group’s most mysterious members: the psychedelic compounds.

Meet the molecules

Empathogens, such as MDMA, promote empathy and compassion. They can be a useful method for revisiting past traumas without fear and anxiety, offering a different point of view – hence their usefulness in tackling PTSD.

Where patients feel overwhelmed by fear and pain, empathogens can let them reframe and reprocess trauma. They might feel a new compassion for themselves, or come across unlikely positive reflections, such as ‘this painful experience made me stronger’.

Evidence suggests that psychedelics may also be neuroplastogens – meaning they promote neuroplasticity and flexible cognition. As such, substances like LSD, 5 -MeO-DMT and psilocybin seem a good fit for escaping the rigid negative mindset of depression or anxiety.

Lili says, “Our thoughts and feelings affect how we perceive the world. Mental health conditions constitute an undue narrowing of experience. These molecules help people increase the number of ways they can perceive reality.”

Some have compared the effects of psychedelics to religious or spiritual transcendence.

The more profound and intense the therapeutic experience, the more lasting the positive effects. If people with depression feel more connected to the world around them during the experience, they have a better chance of overcoming their condition.

Participants in psychedelic trials report feeling ‘part of a bigger picture’ and ‘more connected to myself and the world’.

Researchers posit that ‘deeper’ experiences provide a bigger opportunity to rewire and reset neural connections. It is crucial therefore to use this period of flux to make lasting positive changes (more on this ‘integration’ phase later).

Early evidence shows that neuroplastogens also affect our involuntary inflammation response for weeks after the experience – lessening our body’s harmful overreaction to our environment, and potentially enhancing the growth of new connections between brain cells.

These immunological changes are what the CPRG’s Dr Mary-Ellen Lynall and PhD student Richard Dear are currently investigating, in their study with psilocybin.

Richard says, “Psilocybin affects the immune system, and the immune system is involved in mental illness, so perhaps immune effects will help explain why psychedelic assisted therapy is so effective. It is very exciting to be one of the first groups to investigate this hypothesis.“

“It is so exciting to see work in this area take off in Cambridge.”

Professor Tamsin Ford, Head of the Department of Psychiatry

Your guide to Psychedelic-Assisted Therapy

PAT is delivered over 3 phases.

The preparation phase with a trained therapist can last a few hours. It includes a conversation covering the patient’s history, what they are aiming to address, and what their symptoms are.

This session prepares people for what they might experience during the psychedelic phase. It gives them tools for how to cope with any adverse emotional or physical effects, and helps them avoid becoming overwhelmed. The psychologist also sets down the rules and boundaries of the session, to ensure the patient’s safety.

Next up is the dosing session, where the patient is supervised under the effects of the drug.

For this phase, Lili and her team have transformed a clinical room in Addenbrooke’s Hospital into a welcoming, relaxing space.

The dosing room in the NIHR Clinical Research Facility at Addenbrooke’s Hospital.

The dosing room in the NIHR Clinical Research Facility at Addenbrooke’s Hospital.

This comforting setting helps to increase the likelihood of a positive experience. Patients will be in there a while – depending on the compound, sessions can last between 6 to 8 hours. For all that time, they are under medical supervision and accompanied by a trained therapist.

In many of the current trials, Lili’s team uses ‘inner directed therapy’. Here, the therapist is more like a co-pilot than a guide, letting the patient direct the session in a way that feels right to them.

Lili says, “I’ve had the opportunity to be the therapist in these sessions. It’s really intense and beautiful. Our job in that scenario is not to intervene, but to listen and support.”

Finally, and crucially, comes the integration session. These typically take place the day after dosing, giving the patient time to process and consolidate the experience.

“In these sessions, we sit with the patient and go through what happened,” Lili says. “We support them while they make sense of their experience. They can then integrate these insights into the life they return to.”

Reflecting on their experience of PAT, one participant in an empathogen trial said, “I’d looked at the proposed psychedelic drug trials with apprehension, but was eager to be involved with experiencing a less intensive psychoactive substance.

“Moving through different phases of the study gave me a chance to better explore ‘inner directed therapy’. One of my biggest takeaways is how critical the integrative aspects of PAT will be for future participants to fully experience the neuroplastic effects of these substances.”

Making connections

More people are starting to recognise PAT’s incredible potential.

Earlier this year, CPRG held their first research day, with over 150 people attending. The day was open to academics, clinicians and psychedelic experts from across the UK.

Benjamin Illingworth, PhD student, psychiatrist and CPRG member says, “We want to make sure that these treatments are available to everyone who could benefit. If we don’t create open, expert spaces in which to discuss them, that won’t happen.”

Lili goes further: “Psychedelic therapy shouldn’t be something available only to an elite few who can afford it. These treatments can effectively alleviate mental suffering.

“We are looking for ways to integrate them into the public health system. Our guiding principle is: how can we bring these treatments to the people who need them the most?”

The CPRG are building an evidence base to begin this integration. More clinical trials are in the pipeline for 2026, including a trial of group therapy – where multiple people can receive PAT at the same time.

There are reasons to think PAT will be cost effective for public health systems. Instead of administering existing treatments (therapy and antidepressants) for years, with questionable success rates, PAT is an intense, shorter intervention that tackles the root problem instead of just the symptoms. The hope is that people can fully recover. And if people can join PAT in groups, the clinical team can support many people at once.

Elsewhere in the CPRG, PhD student Anya Ragnhildstveit is collecting experiences and data from people around the world who have received PAT. By bringing together this early evidence, she aims to inform the development of future treatments and shape the design of clinical trials.

The group is also starting to collaborate with others across Cambridge, including consciousness researcher Professor Tristan Bekinschtein, legendary brain scientist Professor Trevor Robbins and cognitive neuroscientist Professor Paul Fletcher.

“There are so many exciting developments coming,” Lili says.

Lili’s enthusiasm is mirrored by Professor Tamsin Ford, Head of the Department of Psychiatry, who says: “It is so exciting to see work in this area take off in Cambridge.“

These fledgling connections are just the start. With its world-renowned neuroscientists, clinicians and psychiatrists, Cambridge provides the perfect meeting place for experts to refine their ideas and shape the treatments of the future.

If you’d like to support the CPRG in providing MDMA-assisted treatments to wounded veterans, you might like to consider making a donation.

Published on 29 October 2025.

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