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The Center for Psychedelic Research is led by a team of interdisciplinary experts who are pioneers in research on psychedelics, meditation, mindfulness, and pain management, with broad support through UC San Diego’s research community.

Our team includes:

  • Mark A. Geyer (Director)

    Mark A. Geyer (Director)

    Mark A. Geyer Ph.D. is Distinguished Professor of Psychiatry and Neurosciences Emeritus at the University of California San Diego and directs the Neuropsychopharmacology Unit of the VISN 22 VA’s Mental Illness Research, Clinical, and Education Center.  Since receiving his doctorate in Psychology in 1972, he has focused on basic research addressing the behavioral and neurobiological effects of psychedelics and other psychoactive drugs.  For four decades, his group has had continuous funding from the National Institute on Drug Abuse to study the behavioral effects of hallucinogens.  In 1993, he co-founded the Heffter Research Institute, which pioneered and supported much of the scientific research that has prompted the exploration of psychedelics as potential therapeutics in humans.  Dr. Geyer is recognized internationally for his research on the psychophysiology, neurobiology, and pharmacotherapy of schizophrenia and bipolar disorder.  He has published over 470 peer-reviewed papers, including many addressing the mechanisms subserving the effects of psychostimulants, hallucinogens, and entactogens.  He is the lead Series Editor for Current Topics in Behavioral Neurosciences, which has completed 43+ volumes.  He was involved intensively in the NIMH-funded MATRICS, TURNS, and CNTRICS Programs.  He has served as a receiving Editor of Neuropsychopharmacology, Neuropharmacology, Psychopharmacology, and Schizophrenia Bulletin, and as Scientific Advisor to European Union’s Innovative Medicine Initiative.  He is a Fellow of AAAS, American College of Neuropsychopharmacology (ACNP), and American Psychological Society, Past-President of the International Society for Serotonin Research and the International Behavioral Neuroscience Society, member of Scientific Council of the Brain and Behavior Research Foundation, 2011 awardee of Bleuler Prize for Research in the Schizophrenias, and the 2014 Julius Axelrod Mentorship Awardee from ACNP.  Dr. Geyer's broad experience as a researcher, grant reviewer, journal editor, and teacher lends invaluable scientific and professional expertise to PHRI, as he provides the leadership to develop a strong program in the behavioral psychopharmacology and clinical applications of psychedelic agents.

  • Adam Halberstadt (Psychopharmacology Director)

    Adam Halberstadt (Psychopharmacology Director)

    Adam L. Halberstadt, Ph.D., received a B.A. in Neuroscience from the University of Delaware in 1998 and a Ph.D. in Neurobiology from the University of Pittsburgh in 2006.  His graduate training focused on the organization of ascending and descending projections from serotonergic nuclei in the brainstem, work that was funded through an individual predoctoral National Research Service award (NRSA) fellowship (F31) from NIDCD.  For his postdoctoral training at the University of California San Diego (UCSD), Dr. Halberstadt received an individual postdoctoral NRSA fellowship (F32) from NIDA to study the behavioral effects of serotonergic hallucinogens.  Dr. Halberstadt has been an Associate Professor of Psychiatry at the University of California San Diego since 2018.   He has received independent funding from NIMH, NIDA, and from the Brain & Behavior Research Foundation.  He is a member of the International Society for Serotonin Research (ISSR, formerly known as the Serotonin Club), and an associate member of the American College of Neuropsychopharmacology (ACNP).  Dr. Halberstadt currently serves as an Associate Councilor for North America for the ISSR and is a member of the IUPHAR Serotonin Receptor Nomenclature Committee.

  • Fadel Zeidan (Neuroscience Director)

    Fadel Zeidan (Neuroscience Director)

    Fadel Zeidan, Ph.D., is an Associate Professor of Anesthesiology at UCSD.  He and his laboratory  have discovered the neural processes supporting mindfulness meditation and mindfulness-based pain relief. Recently, he and his team have demonstrated that mindfulness meditation is mechanistically distinct from and more effective than placebo, distraction, and relaxation. His research is currently funded by the National Center for Complementary and Integrative Health and has disseminated his findings through traditional media outreach (CNN NPR Time Magazine CBS and others), Tedx  and recently personally presented his work to His Holiness, the Dalai Lama in Mongolia. In his new role at the UCSD Center for Mindfulness, Fadel will focus on expanding his research to focus on working with different patient populations and user-friendly approaches to promote the self-regulation of pain. Fadel is especially excited at examining ways to integrate mindfulness from the lab to the clinic and community. 

  • Timothy Furnish (Medical Director)

    Timothy Furnish (Medical Director)

    Timothy Furnish, MD, is Associate Clinical Professor of Anesthesiology and Pain Medicine at UC San Diego where he is director of the pain medicine fellowship program and the Inpatient Pain Service. His practice includes high-risk peri-operative pain, cancer-related pain, and chronic pain management. Dr. Furnish has a master’s degree in social work from the University of Kansas and graduated from Jefferson Medical College in Philadelphia. He completed both his anesthesia residency and pain medicine fellowship at UC San Diego. He has studied, published, and lectured on post-operative pain management, gabapentin-related risks in inpatients, intrathecal drug delivery, the use of cannabinoids for the treatment of pain, and potential analgesic mechanisms of classical psychedelics.

  • Joel Castellanos (Associate Medical Director)

    Joel Castellanos (Associate Medical Director)

    Joel Castellanos, MDis a board-certified physical medicine and rehabilitation and pain medicine physician, and serves as medical director of Inpatient Rehabilitation. Dr. Castellanos’ prime focus is improving function using an individualized approach. He is particularly interested in neuromodulation at various levels including spinal cord stimulation and peripheral nerve stimulation, interventional spine procedures, radiofrequency neurotomy, ultrasound-guided and fluoroscopically-guided procedures, and regenerative medicine such as platelet-rich plasma, stem cells, and Tenex (minimally invasive technology for treatment of chronic pain). He has specific clinical interests in pelvic pain, complex regional pain syndrome, phantom limb pain, and post-spinal cord injury pain syndromes. His research interests include altering nutrition as a means of treating chronic pain, neuromodulation for chronic painful conditions as well as the potential use of psychedelics for these conditions. An associate professor in the Department of Anesthesiology at UC San Diego School of Medicine, Dr. Castellanos instructs pain medicine fellows, as well as medical students, residents in their pain rotations. Dr. Castellanos completed his fellowship in pain medicine at UC San Diego School of Medicine. He completed residency training in physical medicine and rehabilitation at University of Michigan Medical School, where he also he completed a two-year program in healthcare administration. Dr. Castellanos earned his medical degree from University of Toledo College of Medicine in Ohio. He is board certified in physical medicine and rehabilitation and pain medicine.
  • Cassandra Vieten (Psychology Director)

    Cassandra Vieten (Psychology Director)

    Cassandra Vieten, PhD, is a professor, licensed clinical psychologist, mind-body medicine researcher, author, consultant, and internationally recognized workshop leader and public speaker. Her current research projects focus on establishing training guidelines for spiritual and religious competencies for mental health professionals; developing and delivering wellness programs for law enforcement agencies, officers and professional staff; developing virtual reality tools and experiences designed to induce perspective shifts that change people's worldviews; investigating the nature and potentials of imagination: and studying the therapeutic potential of psychedelics.

    Cassi is a Clinical Professor in the Department of Family Medicine's Centers for Integrative Health at the University of California, San Diego, where she serves as the Director of the Center for Mindfulness. The CFM is one of the leading mindfulness centers in the country, offering courses in mindfulness to the general public, conducting research on mindfulness-based interventions (MBIs), incubating new MBIs for special populations and settings, and training and certifying professional mindfulness teachers.

    She is also Director of Research at the Arthur C. Clarke Center for Human Imagination at UC San Diego. The Clarke Center advances understanding of the phenomenon of imagination and its practical applications. We research, enhance, and enact the gift of human imagination by bringing together the inventive power of science and technology, with the critical analysis of the humanities, and the expressive insight of the arts. And, we work to develop more effective ways of using imagination to cultivate public engagement with the big questions of our time, to improve education and learning, and to enhance the application of imagination in meeting humanity’s challenges.

    Cassi is also co-founder and Clinical Psychology Director at the Psychedelics and Health Research Initiative at UCSD, where a flagship study focuses on psilocybin for phantom limb pain in patients with amputations.

    She is Senior Advisor at the John W. Brick Mental Health Foundation, where she served as Executive Director from 2019-2023. Founded by Victor and Lynne Brick, in honor of Victor’s brother John who suffered from schizophrenia, the JWB Foundation funds and promotes empirical research on fitness, nutrition, and mind-body approaches to foster mental health, and to better prevent and treat mental illness.

    Cassi is a Senior Fellow at the Institute of Noetic Sciences (IONS), founded by Apollo 14 Astronaut Edgar Mitchell, where she worked for 18 years. She served as CEO/President from 2013-2016 and President from 2016-2019. The mission of IONS is revealing the interconnected nature of reality through scientific exploration and personal discovery, creating a more just and thriving world. In addition to her contributions to the overall mission, vision, strategic direction, financial health, board and staff development, and activities of the organization, she headed up several initiatives including Mindful Motherhood, Living Deeply and the Transformation Project, and the Future of Meditation Research Project.

    She is co-chair of the Board of Directors of Partners for Youth Empowerment, Vice-Chair of the Board of Directors of the Consciousness and Healing Initiative, and serves on the Board of the Virtual World Society.

  • Albert Yu-Min Lin (Director of Exploration)

    Albert Yu-Min Lin (Director of Exploration)

    Albert Yu-Min Lin, Ph.D., is an award-winning scientist, technologist, explorer, and storyteller (both on state and the big screen). His work to reinvent how we explore has made headlines around the world, merging adventure with innovation. His projects range from an effort to search for the tomb of Genghis Khan in Mongolia (using satellites, crowdsourcing, drones, and ground generating radar), to expeditions remapping major sites from the deserts of Jordan to the jungles of Guatemala (with aerial and ground based Lidar), to his most recent efforts to redefine human bionic capabilities through 3D prosthetics and "flow experiments". Albert is a UC San Diego Research Scientist, a National Geographic Explorer, and a curious human. He is co-author, with Drs. Ramachandran and Furnish, and the subject of the first case study of using psilocybin to treat phantom-limb pain.

  • Jon Dean, Ph.D. (Director of DMT Division)

    Jon Dean, Ph.D. (Director of DMT Division)

    Jon Dean, Ph.D., is a postdoctoral scientist in the Brain Mechanisms of Pain and Health Laboratory at UC San Diego’s Department of Anesthesiology. After obtaining his B.A. in Chemistry from Youngstown State University, Dr. Dean completed his Ph.D. in Molecular and Integrative Physiology from the University of Michigan. His previous work discovered that biosynthesis of the psychedelic N,N-dimethyltryptamine (DMT) occurs in the living rat brain and that the prefrontal cortex plays a pivotal role in regulating consciousness through cholinergic mechanisms. Eager to expand his research to human patient populations, he is now developing the skills to lead an independent research program to determine the neural mechanisms supporting the promotion of well-being and the cultivation of empathy and compassion by mindfulness meditation and psychedelics. To this extent, Dr. Dean has recently been recognized as a Sanford Fellow by the UCSD T. Denny Sanford Institute for Empathy and Compassion where he will examine the mechanisms supporting empathy promotion by psilocybin-assisted therapy.

  • Sidney Zisook

    Sidney Zisook

    Sidney Zisook, M.D., is a Distinguished Professor of Psychiatry UC San Diego. He directs the UC San Diego Healer Education, Assessment and Referral (HEAR) program, dedicated to preventing/reducing nurse and physician mental health stigma, burnout, and suicide. He serves on the Scientific Review Board and Grant Review Committee of the American Foundation for Suicide Prevention (AFSP), Scientific Advisory Board of the Depression and Bipolar Support Alliance (DBSA), Board of Directors of the American College of Psychiatry and the Board of Directors of the American Society of Clinical Pharmacology. He is the UC San Diego PI on an industry-sponsored multi-site study assessing psilocybin-assisted psychotherapy for treatment resistant depression. He has recently served as the National Co-Chair of a 35-site VA Cooperative Study on Treatment Resistant Depression, PI of a NIMH research study assessing treatment of Complicated Grief and an AFSP-supported intervention study providing grief-focused psychotherapy for individuals who have lost a loved one to suicide. He was the founding president of the San Diego Board of Directors for the AFSP and PI of the John A. Majda MD Memorial Fund dedicated to facilitating research related to de-stigmatizing depression and preventing physician suicide. Over his career, he has published extensively on the treatment of depression, suicide prevention, grief and bereavement, and psychiatric education. 

  • Erik Viirre

    Erik Viirre

    Erik Viirre, MD, Ph.D., Director of the Arthur C. Clarke Center for Human Imagination at UC San Diego, Adjunct Professor of Neurosciences, Medical Director of the Qualcomm Tricorder XPRIZE, and healthcare technology innovator developing the future of medicine and visual consciousness research. He works with people who have disorders of their acceleration and gravity senses: the vestibular system, which is crucial for balance and even more important for conscious visual experience of the world. His research has shown how the brain coordinates the eyes and his medical work focuses on two of the most common conditions that affect the brain and thinking: migraine and head injury. As a technologist, Erik has helped develop Virtual Reality technologies, such as displays that scan lasers directly into the eyes, and brain monitoring techniques, for which he has 5 patents. A professional in aviation and space, Erik is a sea and instrument rated pilot. When Chief Medical Officer of Zero G, the airline that provides weightlessness, he was the team lead on missions to take Stephen Hawking, among others, into Microgravity. Dr. Viirre has done research for the National Institutes of Health, the United States Navy’s Office of Naval Research, DARPA and NASA. Dr. Viirre received his Ph.D. in Neurophysiology in 1987 at the University of Western Ontario in London, Canada and his M.D. in 1988. He completed a Rotating Internship at St. Josephs's Medical Center in London, Canada in 1989. After his internship in London, he was a fellow at the Robarts Research Institute in functional imaging and had an eye care practice. In 1994, Dr. Viirre was a Visiting Professor in Neurology and Ophthalmology at UCLA where he did a fellowship in Medical Neurotology, the management of inner ear disorders. In 1995-99 he was a Scientist at the Human Interface Technology Lab at the University of Washington. He was a Senior Scientist in the Human Performance Department of the US Navy’s Naval Health Research Center from 2001 to 2012 and is a member of the Clinical Investigation Department at Naval Medical Center San Diego as of 2012.

  • Ethan Hurwitz

    Ethan Hurwitz

    Ethan Hurwitz is a PhD student in the UC San Diego Department of Psychology and the CPR's Research Excellece Fellow for 2023-24. Before beginning his graduate training, he worked as a research coordinator for Dr. Roland Griffiths at the Johns Hopkins Center for Psychedelic & Consciousness Research. There he worked on projects which aimed to better characterize both the phenomenology and enduring effects of pharmacologically-induced altered states of consciousness, with particular emphasis on their clinical applications. He currently works with Dr. Adena Schachner investigating social cognition through probabilistic computational models.

  • Patrick Coleman

    Patrick Coleman

    Patrick Coleman is the Managing Director for the CPR, as well as the Assistant Director of the Arthur C. Clarke Center for Human Imagination at UC San Diego, where he oversees planning for multiple research projects and programs that illuminate the neurological, cognitive, and cultural components of imagination. Among other projects, he co-organized the Art + Empathy Lab, funded by the California Arts Council’s Research in the Arts program, which presents a comprehensive perspective of attention, arousal, empathic response, and emotional regulation in real-world encounters with art through in-gallery research using multi-modal biometric data collection, machine learning, computer vision, and psychometrically validated subjective data with partners at the San Diego Museum of Art. Prior to the Clarke Center, he managed interdisciplinary collaborations as an assistant curator at the San Diego Museum of Art, including the exhibition The Art of Music and accompanying scholarly catalogue. He received a B.A. from the University of California Irvine and an M.F.A. from Indiana University.
  • Ethan Badger

    Ethan Badger

    Ethan Badger, MAS, is the clinical research coordinator for the CPR.