Prof. Zach Walsh
RPsych, Professor
Type of Practice:
Researcher - Clinical Psychologist

Education Associations

PhD, BC College of Psychologists, UBC

Professional Associations

University of British Columbia


Zach Walsh, PhD, RPsych is a clinical psychologist, a Professor of Psychology at the University of British Columbia, and a Research Affiliate with the BC Centre on Substance Use. He has published and presented widely on topics related to cannabis and mental health. His research has been supported by CIHR, SSHRC and others and he has been lead investigator for several studies of cannabis use including a clinical trial of cannabis for PTSD. Zach has provided invited consultations on medical cannabis use to the Canadian House of Commons and Senate, the Uruguayan Ministry of Health and other international organizations.


Lucas P, Boyd S, Milloy MJ, Walsh Z. (in press). Reductions in alcohol use following medical cannabis initiation: results from a large cross-sectional survey of medical cannabis patients in Canada. International Journal of Drug Policy

Capler, R., Lucas, P. & Walsh, Z. (in press). The Medical Cannabis Standards Engagement Evaluation and Dissemination (SEED) project: A community-based research approach to self-regulating medical cannabis dispensaries in Canada. International Journal of Drug Policy

St. Pierre, M., Russo E. & Walsh, Z. (2020) No evidence of altered reactivity to experimentally induced pain among regular cannabis users. Clinical Journal of Pain, 36, 589-593

Walsh, Z. (2020). Cannabis epistemology and the case-series design: An invited commentary on a case series and dismissive response. Journal of Alternative and Complementary Medicine, 26, 259-260

St. Pierre, M., Matthews, L. & Walsh, Z. (2020). Cannabis education needs assessment among Canadian physicians-in-training. Complementary Therapies in Medicine, 49

Lake, S., Kerr, T., Buxton, J., Walsh, Z., Marshall, B.D., Wood, E. & Milloy, M.J. (2020). Does cannabis use modify the effect of post-traumatic stress disorder on severe depression and suicidal ideation? Evidence from a population-based cross-sectional study of Canadians. Journal of Psychopharmacology, 34, 181-188.

Walsh, Z., (2019) A crude approach to evaluating cannabis legalization, Canadian Medical Association Journal, 191, 109

Walsh, Z., Gonzalez, R., Crosby, K., Thiessen, M.S., Carroll, C., & Bonn-Miller, M.O., (2017). Medical cannabis and mental health: A systematic and guided review. Clinical Psychology Review, 51, 15-29.

Lucas, P. & Walsh, Z., (2017). Medical cannabis access, use, and substitution for prescription opioids and other substances: A survey of authorized medical cannabis patients. International Journal of Drug Policy, 42, 30-35.

Walsh, Z., Callaway, R., Belle-Isle, L., Capler, R., Kay, R., Lucas, P., & Holtzman, S. (2013). The Cannabis Access for Medical Purposes Study: Patient characteristics, reasons for use, and modes of access. International Journal of Drug Policy, 24, 511-516.