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About PHRI

The Psychedelics and Health Research Initiative (PHRI) at UC San Diego conducts novel basic and clinical research on the use of psychedelics for the treatment of pain and other health conditions.

Significant evidence has emerged in the last fifteen years that shows how classical psychedelics, such as psilocybin (the major psychoactive compound in “magic mushrooms”), can be used to treat depression, anxiety, addiction, and other psychological disorders. Pain has both physical and affective/cognitive components, and our promising preliminary findings indicate that psychedelics, alone or as part of multi-pronged treatment, can produce significant, meaningful, and lasting reductions of chronic pain conditions like cluster headache, complex regional pain disorder, phantom-limb pain, tinnitus, and others. As a non-addictive alternative to opioids, psychedelics represent a revolutionary and much-needed new approach to the treatment of pain.

The interdisciplinary PHRI team of leading researchers conducts pilot studies, clinical trials, and brain imaging research to better understand how psychedelics can be used to treat pain, the mechanisms of action by which they produce their effects, how this illuminates new aspects of the healthy functioning of the brain and mind, and how the healthcare system can adapt to best deliver these radically different modes of intervention, all in the context of UC San Diego’s world-class health and neuroscience research communities.


The last fifteen years have seen the rising prominence of research into how classical psychedelic drugs (primarily LSD and psilocybin, the major psychoactive compound in “magic mushrooms”) can be used to treat depression, anxiety, addiction, and other psychological disorders. Phase III clinical trials are now being planned on the basis of this research. Psilocybin received a Breakthrough Therapy Designation from the FDA in 2018. However, a new emerging body of evidence, piloted by UC San Diego researchers, among others, suggests that psychedelics may revolutionize another area of health treatment at the intersection of mind and body: pain.

Arising from physical damage but intrinsically a cognitive and emotional experience, pain can be debilitating and treating it is complex, expensive, often inadequately effective, and, as the opioid crisis has shown, not without dire side effects. Non-opioid treatments for pain conditions—like cluster headache, complex regional pain disorder, phantom-limb pain, tinnitus, and other forms of chronic pain—could mean radical improvements for the over 100 million sufferers in the United States alone, as estimated by the Centers for Disease Control and Prevention.

The psychedelic psilocybin, the active compound in “magic mushrooms,” has demonstrated significant power to alleviate treatment-resistant depression, anxiety, addiction, and for use in end-of-life care. A growing body of research suggests that one or two sessions of psychedelic-assisted therapy, in a supportive clinical environment, can result in a transformative reduction in pain.

Psychedelics and Pain

In the first published case study on using psilocybin to treat phantom-limb pain, co-authored by Timothy Furnish (UCSD), Albert Yu-Min Lin (UCSD), and V.S. Ramachandran (UCSD), a single session with psilocybin resulted in immediate, persistent, and profound reduction in what had been debilitating pain caused by a post-trauma amputation. One possible explanation, based on existing research and theory, is that psilocybin is effective against phantom limb pain because it can increase neuroplasticity in the brain, allowing new functional connections and pathways to form in the regions responsible for body image and the mental phenomenon of pain.

The use of psilocybin to treat phantom limb pain has not been previously documented in the literature. Yet, there is intriguing overlap with the brain imaging research of Fadel Zeidan (UCSD) on using mindfulness meditation as a treatment for pain. This research shows that mindfulness engages a non-endogenous opioid pain pathway in the brain. Recent research on psychedelics has shown they produce similar states of mind and brain connectivity as experienced meditators, and that the two—psychedelics and mindfulness—are mutually supportive.

PHRI Research Program

To follow-up on these important findings, the Psychedelics and Health Research Initiative at UC San Diego has organized a research program to catalyze understanding of the potential for psychedelics and related adjuncts to treat pain. These include:

  1. pilot studies and clinical trials
  2. collecting supplementary fMRI, EEG, and other biometric and cognitive data from study participants to investigate how brain/body dynamics are affected by the psychedelic experience and to establish baseline measures that can be used to evaluate other treatment methods
  3. developing new clinical, ethical, and legal frameworks for how these treatments can best be integrated into the healthcare system.

Through the Psychedelics and Health Research Initiative, we seek to better understand the nature and outcomes of these tools and the mechanisms by which they function, with the goal of developing the methodology and understanding required to apply these insights to improve the lives of pain sufferers.

PHRI at UC San Diego

The Psychedelics and Health Research Initiative is a collaboration between the Arthur C. Clarke Center for Human Imagination, the Center for Human Frontiers at UC San Diego’s Qualcomm Institute, the Center for Mindfulness, and the departments of Anesthesiology and Psychiatry at UC San Diego School of Medicine.


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