Psychedelic-Assisted Therapy in Trauma Recovery
To understand why psychedelic-assisted therapy is attracting so much attention today, it’s important to understand its history.
Psychedelic research is not new. During the 1950s and 60s, scientists and psychiatrists were already studying LSD and psilocybin and exploring their possible use in mental health treatment. Psilocybin itself has a much longer history of use among Indigenous peoples in Mexico and Central America. Michael Pollen describes this early research in How to Change your Mind. At the time, there was considerable interest in whether psychedelics could be used alongside psychotherapy. However, this research was eventually interrupted.
During the 1960s, LSD became closely associated with the counterculture, a social movement in which many young people challenged traditional ideas about authority, politics, war, and society. LSD became particularly associated with the anti-Vietnam war movement and wider political protest. As quickly as psychedelics had gained attention in the cultural and scientific world, they became increasingly controversial.
David Nutt argues in Psychedelics: The Revolutionary Drugs That Could Change Your Life that this political history is important when we look at why psychedelics were eventually prohibited. In the U.S., the Controlled Substances Act of 1970 placed LSD and psilocybin in Schedule 1. This made research much more difficult by restricting access to the drugs and creating major barriers to clinical research and funding.
Pollan describes this period as a major interruption in psychedelic science. It was not simply a case of scientists deciding that psychedelics did not work. Research became extremely difficult at a time when the drugs were also surrounded by political and social controversy.
This history has contributed to some of the myths surrounding psychedelics. Because these substances have been controlled and prohibited, they are sometimes described as either completely dangerous or completely ineffective.
Psychedelics can have real risks, particularly when they are used without appropriate screening, supervision, or a controlled safe environment. At the same time, research is showing that some of these substances may have therapeutic potential when used carefully and safely alongside psychological support.
From the 1990s onwards, researchers began returning to questions that had been left unanswered for decades. Modern clinical trials and brain-imaging technology gave scientists new ways to study psychedelics. Researchers could now investigate not only what people experienced during a psychedelic session, but also what was happening in the brain and whether these experiences could be linked to improvements in mental health.
In How to Change Your Mind, Michael Pollan explores the history of psychedelics and their research into consciousness, depression, addiction, and anxiety. David Nutt's Psychedelics: The Revolutionary Drugs That Could Change Your Lifelooks at the neuroscience, risks, and possible therapeutic uses of these substances. Nutt's major argument is that psychedelics should be assessed according to scientific evidence rather than simply their historical reputation or legal classification.
One of the strongest areas of research is psilocybin and depression.
Depression can make people feel trapped in the same negative thoughts and patterns. Researchers are interested in whether psilocybin can temporarily loosen these patterns and give people a different perspective on themselves and their lives.
Johns Hopkins and NYU have been particularly important in this research. In 2016 trials, they studied people experiencing depression and anxiety after receiving a life-threatening cancer diagnosis. “In both the NYU and Hopkins trials, 80% of cancer patients showed clinically significant reductions in standard measures of anxiety and depression, an effect that endured for at least 6 months after their psilocybin session” (Pollan 349).
Johns Hopkins researchers later studied psilocybin specifically in people with major depressive disorder. A 2021 randomized clinical trial found significant reductions in depressive symptoms following psilocybin-assisted therapy.
These findings don’t mean that psilocybin is a cure for depression. The studies were carefully controlled and involved psychological support. Researchers are still investigating how long the benefits last, who benefits most, and how psychedelic therapy compares with existing treatments. However, the results are encouraging enough that psilocybin is now one of the most studied psychedelic treatments for depression.
One of the most interesting questions is what psychedelics actually do to the brain. Brain-imaging studies suggest that psilocybin changes the way different areas of the brain communicate. A 2024 study using detailed brain scans published in Nature found that psilocybin significantly disrupted normal patterns of brain connectivity. The researchers described this as a temporary "desynchronization" of brain networks, meaning that areas that normally communicate in predictable patterns became less tightly connected. Some changes remained for several weeks.
These findings may help explain why some people describe psychedelic experiences as giving them a new perspective or making their usual ways of thinking feel less fixed. Depression, anxiety, and addiction can involve the brain getting stuck in a rigid, negative loop pattern. By temporarily changing how different brain networks communicate, psilocybin may create a period of greater neuroplasticity, allowing the brain to be more open to new ways of thinking and behaving.
Across studies, psychedelics promotes neuroplasticity, which is the brain's ability to change and adapt, allowing people to physically break out of deeply ingrained, compulsive neural loops.
When it comes to PTSD and trauma, MDMA has shown some of the strongest results in psychedelic-assisted therapy. Unlike psilocybin and LSD, MDMA is an entactogen, meaning it can increase feelings of emotional connection, empathy, and openness.
Researchers believe these effects may help people revisit traumatic memories with less fear and emotional distress while working with a therapist. In a Phase 3 clinical trial, involving 90 people with severe PTSD, those who received MDMA-assisted therapy experienced a significantly greater reduction in PTSD symptoms than those who received therapy with a placebo. A second Phase 3 trial involving 104 people with moderate-to-severe PTSD, published in Nature Medicine in 2023, found similar results.
These findings suggest that MDMA-assisted therapy may help change how people process traumatic memories. However, the therapy involves more than the drug itself, it involves preparation, professional support, therapy, and integration.
Addiction is another area that has interested psychedelic researchers for decades.
A 2022 NYU trial published in JAMA Psychiatry studied psilocybin-assisted psychotherapy for alcohol-use disorder. The results showed a significant decrease in heaving drinking (83% reduction) compared to placebo group.
Another study by John Hopkins pilot and long-term follow up showed psilocybin sessions with CBT for longtime smokers showing an 80% abstinence rate at 6 months.
The results are promising, but the evidence is still smaller for addicion than the evidence for depression and PTSD primarily due to funding limits and strict drug laws not lack of efficacy. Nutt argues that because alcohol is the most harmful to society, using psychedelics to break the rigid neural loops of addiction could ultimately have the largest overall public health impact.
Overall, psilocybin has particularly promising evidence for depression and end-of-life anxiety, with research also exploring addiction and other conditions such as OCD and anorexia which are promising but still growing. MDMA-assisted therapy has shown strong results for PTSD and trauma. LSD has a much longer history of research into psychotherapy and addiction, but due to severe prohibition and stigma it created a limited role in modern psychedelic research.
Across these studies, researchers are interested in similar ideas: whether psychedelics can temporarily change rigid patterns of thinking, alter emotional processing, and create an opportunity for psychological change. But the psychedelic experience is only one part of the treatment.
The strongest research involves preparation, professional support, a carefully controlled environment, and therapy or integration afterwards. That is why psychedelic-assisted therapy is very different from taking a psychedelic drug on your own.
For decades, psychedelics were discussed in terms of danger, illegality, and counterculture. Today, psilocybin, MDMA, and other psychedelics are being studied as possible tools for treating mental health conditions, while researchers continue to investigate their risks and limitations.
The results so far are promising enough that psychedelics are once again being taken seriously as a subject of scientific research due to proving efficacy. The focus of modern research is now on understanding who can benefit, how these treatments work, how long the benefits last, and how they can be used safely.
Resources
Bogenschutz, Michael P., et al. "Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder: A Randomized Clinical Trial." JAMA Psychiatry, vol. 79, no. 10, 2022, pp. 953–962. doi:10.1001/jamapsychiatry.2022.2096.
Davis, Alan K., et al. "Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder: A Randomized Clinical Trial." JAMA Psychiatry, vol. 78, no. 5, 2021, pp. 481–489. doi:10.1001/jamapsychiatry.2020.3285.
Griffiths, Roland R., et al. "Psilocybin Produces Substantial and Sustained Decreases in Depression and Anxiety in Patients with Life-Threatening Cancer: A Randomized Double-Blind Trial." Journal of Psychopharmacology, vol. 30, no. 12, 2016, pp. 1181–1197. doi:10.1177/0269881116675513.
Johnson, Matthew W., et al. "Pilot Study of the 5-HT2AR Agonist Psilocybin in the Treatment of Tobacco Addiction." Journal of Psychopharmacology, vol. 28, no. 11, 2014, pp. 983–992. doi:10.1177/0269881114548296.
Mitchell, Jennifer M., et al. "MDMA-Assisted Therapy for Severe PTSD: A Randomized, Double-Blind, Placebo-Controlled Phase 3 Study." Nature Medicine, vol. 27, 2021, pp. 1025–1033.
Mitchell, Jennifer M., et al. "MDMA-Assisted Therapy for Moderate to Severe PTSD: A Randomized, Placebo-Controlled Phase 3 Trial." Nature Medicine, vol. 29, 2023, pp. 2473–2480. doi:10.1038/s41591-023-02565-4.
Nutt, David. Psychedelics: The Revolutionary Drugs That Could Change Your Life: A Guide from the Expert. Yellow Kite, 2023.
Pollan, Michael. How to Change Your Mind: The New Science of Psychedelics. Penguin Books, 2019.
Ross, Stephen, et al. "Rapid and Sustained Symptom Reduction Following Psilocybin Treatment for Anxiety and Depression in Patients with Life-Threatening Cancer: A Randomized Controlled Trial." Journal of Psychopharmacology, vol. 30, no. 12, 2016, pp. 1165–1180.
Siegel, Joshua S., et al. "Psilocybin Desynchronizes the Human Brain." Nature, vol. 632, 2024, pp. 131–138. doi:10.1038/s41586-024-07624-5.
