Dr. Joe Tafur, M.D. has spent his career in psychedelic research trying to bridge the gap between Western medicine and spiritual healing systems. Modern science, he reasons, has given us a wealth of technology and drugs to try to heal illness and disease, while often minimizing the role of emotional and spiritual health.

Tafur spent several years in Peru’s Amazon studying the ancient shamanic tradition of the Shipibo under the guidance of Ricardo Amaringo—a master ayahuasquero. This practice makes use of the ayahuasca brew, containing the powerful hallucinogen DMT. Through these experiences, Tafur learned how the spirit and the physical body interact to heal us.

Today, Tafur is spearheading the Modern Sprit Epigenetics Project, an ambitious study in how psychedelic medicine works at the most fundamental level: that of our DNA. Epigenetics is a scientific field which studies ‘gene expression,’ the process through which protein production in our cells, mediated by DNA, is affected by environmental changes. In Tafur’s project, his team aims to show a biological basis for how MDMA (the purest form of “ecstasy”)-assisted psychotherapy can help patients heal from post-traumatic stress disorder (PTSD).

Modern Spirit has partnered with the Multidisciplinary Association for Psychedelic Studies (MAPS), who are sponsoring clinical trials of MDMA treatment for PTSD throughout North America, Europe, and Asia. Tafur’s team will collect and analyze saliva samples from trial participants before, during, and after their treatment to explore what physiological impact the combination of MDMA and psychotherapy have on participants.

“You have your DNA code, the ‘blueprint’ for how proteins are made,” Tafur explains. “Think of it like the ‘hardware,’ and then you have the ‘software’ that reads that blueprint. It alters the expression of your genes in response to what happens in the environment.”

Different environmental influences and events in our life can cause a change in how our genes do their work. Epigenetics is distinct from mutations, which are actual changes in the DNA code itself.

Genes comprised of DNA direct protein production in the cells, and they can work faster, slower, or not at all, like a volume knob or a switch. So epigenetics concerns itself with how this ‘programming’ is changed by our environments, and why. Epigenetic changes may form the basis of many physical factors in our bodies that make us unique, like how fast we age, our psychology, and even diseases.

“There is no question that epigenetics are of great interest in present psychiatric research,” says Dr. Kenneth Alper, M.D., a psychiatrist who has studied the use of ibogaine for substance-use disorder. “Modern Spirit is doing what good psychiatric geneticists are supposed to do, they’ve identified an interesting sample of opportunity. It’s good scientific creative thinking.”

What’s unique about the Modern Spirit project, Alper contends, is it’s taking a well-established approach to understanding mental illness and applying that to the relatively poorly understood field of psychedelics. “It’d be a real shame if all these patients went through the MDMA trials without getting swabbed and their DNA samples being saved. This is a really astute inquiry to take.”

Modern Spirit’s work is concerned with epigenetic change brought about by trauma. “We’re looking for things like little biomolecular ‘tags’ that can be placed on the DNA strand or the protein that packages it,” Tafur says. “There’s other mechanisms we can look at, for example, the cortisol receptor.”

Cortisol is the stress hormone. Tafur explains that PTSD disturbs cortisol cycles; which becomes problematic because the hormone activates a receptor on our cells. And the genetic expression of that receptor is known to be influenced epigenetically. Research shows that heavily traumatized people have a different expression of the receptor.

Epigenetic changes caused by trauma can be passed down to our descendants, a phenomenon called “intergenerational trauma.” Tafur referenced a study by Brian G. Dias and Kerry J. Ressler in which the researchers conditioned laboratory mice into fearing a specific chemical odor by administering electric shocks. The mice passed this fear response on to their children and grandchildren, who would react with fear—without being shocked—when they smelled the same chemical.

So how does trauma get inherited? Dr. Monnica T. Williams, Ph.D., a principal investigator for an MDMA for PTSD study based at the University of Connecticut (UConn), is focused on people of color and a phenomenon known as ‘cultural trauma’. These traumas are shared among nations and groups of people through oppression, war, or genocide.

“Up until those first epigenetic studies with mice, we thought that cultural trauma was transmitted socially,” Williams says. “So for example, I have bad experiences with police, then I tell my children to stay away from them or they see my fear when police are around and they inherit my fear.

In light of new research, however, Williams explains that fear can be biologically transmitted.

“So I could have had bad experiences with police, and never shared them with my kids [and yet] they still end up having this fear,” she says. “Over generations, where a culture of people have been oppressed and harassed by law enforcement, you can see how cultural trauma develops and is propagated.”

Cultural or intergenerational trauma can have devastating health effects for whole populations and communities of people. PTSD, then, is a way in which epigenetic changes can occur, Williams explains, and cultural trauma is expressed. “We know that trauma can result in anxiety, depression, substance abuse, agoraphobia, and many other types of mental health problems.”

People can develop PTSD when the mind is subject to repeated trauma, causing one to lose the ability to process and make meaning of those experiences. People also suffer the effects of stigma and shame attached to the healing process if they cannot recover quickly enough or do not seek outside help.

“But what happens with MDMA is that it lowers the anxiety, stress, and shame around the traumatic event,” Williams says. “So people can talk to their therapist in a more open way or process it on their own and approach those memories they’ve been avoiding. That natural processing happens and they’re able to recover and move forward.”

Thus, these improved psychological patterns may represent epigenetic adaptations that can be passed on to descendants.

Modern Spirit is currently raising about $200,000 to fund their laboratory research, which is expensive to conduct. But Tafur explains that there’s been a massive explosion of interest in the biology of epigenetic research. “Its role in mental health can’t be questioned,” Tafur says. “There’s also evidence for epigenetic disturbance in anxiety and depression. We simply need to collect more data.”

Tafur believes that the research into how MDMA treatment works can open the door for future science on many other forms of spiritual healing. Furthermore, he explains that epigenetics is a very sensitive element of our biochemical machinery that we don’t have the direct mechanisms to understand just yet.

“We don’t know how psychotherapy, meditation, or altered states of consciousness alter our epigenetics—we just know they do…” he says. “If we have a better understanding of why MDMA treatment works, we can then focus on anything from somatic experiencing therapy to breathwork, and explore how these spiritual techniques facilitate healing.”