Evidence is most valuable when it moves beyond the page.
My work has contributed to research, international guidance, national health initiatives and policy conversations across substance use, mental health, population health and emerging technologies.
A selection of that work is highlighted below.
Technical Reports & Contributions to Policy and Practice
Canadian Centre on Substance Use and Addiction. Acquired Brain Injury and Substance Use Health. Capacity: Senior Research and Policy Analyst.
World Health Organization. Chapter Alcohol Taxation Manual: A health promotion approach to alcohol taxation. Leos-Toro C, Tello JE, Rekve D, et al. Forthcoming. Capacity: Consultant, lead.
World Health Organization. Briefing Note: Health promotion approaches to alcohol use and inequalities. 2022. Geneva, Switzerland. Capacity: Consultant, lead.
World Health Organization. Briefing Note: Mitigating the impact of unrecorded alcohol. 2022. Geneva, Switzerland. Capacity: Consultant, lead.
World Health Organization. Briefing Note: Health warning labels on alcohol products: Opportunities for informed and healthier choices. 2022. Geneva, Switzerland. Capacity: Consultant, lead.
World Health Organization. Briefing Note: Addressing and managing conflict of interest in alcohol control policies. 2022. Geneva, Switzerland. Capacity: Consultant, lead.
Leos-Toro C, Shanahan L, Quednow BB. Impact of the COVID-19 crisis on addictive behaviours in the population and care for individuals experiencing substance use disorders. 2021. Swiss School of Public Health (SSPH+).
World Health Organization - United Nations Office on Drugs and Crime. International Standards for the Treatment of Drug Use Disorders – Revised Edition Incorporating Results from Field Testing.2020. Geneva, Switzerland. Capacity: Consultant.
World Health Organization. ATLAS on Substance Use 2017. 2018. Geneva, Switzerland. Capacity: Consultant.
Leos-Toro C, Reid JL, Madill CL, Rynard VL, Manske SR, Hammond D. Cannabis in Canada - Tobacco Use in Canada: Patterns and Trends, 2017 Edition, Special Supplement. Waterloo, ON: Propel Centre for Population Health Impact, University of Waterloo.
World Health Organization - United Nations Office on Drugs and Crime. International Standards for the Treatment of Drug Use Disorders – Draft for Field Testing.Commission on Narcotic Drugs 59th Session, 2016. Geneva, Switzerland. Capacity: Consultant.
World Health Organization. The Health and Social Effects of Nonmedical Cannabis Use. 2016. Geneva, Switzerland. Capacity: Intern.
Leos-Toro C, Liao V, Nunn J, Salgado, L. Examining School Outcomes of Late-Preterm Infants. 2013. Knowledge Impact Strategies Consulting Ltd: Waterloo, ON. www.kimpact.ca PhD Dissertation
Health Warnings, Cannabis Marketing and Perceptions among Youth and Young Adults in Canada
Peer-Reviewed Works
Goodman, S., Leos-Toro, C., Hammond D. (2022). Do Mandatory Health Warning Labels on Consumer Products Increase Recall of the Health Risks of Cannabis?Substance Use & Misuse, DOI: 10.1080/10826084.2021.2023186
Leos-Toro, C., Ribeaud, D., Bechtiger, L., Steinhoff, A., Nivette, A., Murray, A.J., Hepp, U., Quednow, B.B., Eisner, M.P., Shanahan, L. (2021). Attitudes toward COVID-19 vaccination among young adults in Zurich, Switzerland, September 2020.International Journal of Public Health. https://doi.org/10.3389/ijph.2021.643486
Leos-Toro, C., Fong, G.T., Hammond, D. (2021). The efficacy of health warnings and package branding on perceptions of cannabis products among youth and young adults.Drug and Alcohol Review. https://doi.org/10.1111/dar.13240
Sikorski, C., Leos-Toro, C., Hammond, D. (2021). Cannabis Consumption, Purchasing and Sources Among Young Canadians: The Cannabis Purchase and Consumption Tool (CPCT).Substance Use & Misuse. https://doi.org/10.1080/10826084.2021.1879142
Leos-Toro, C., Fong, G. T., Meyer, S. B., & Hammond, D. (2020). Cannabis health knowledge and risk perceptions among Canadian youth and young adults.Harm Reduction Journal, 17(1), 54. https://doi.org/10.1186/s12954-020-00397-w
Leos-Toro, C., Fong, G. T., Meyer, S. B., & Hammond, D. (2020). Cannabis labelling and consumer understanding of THC levels and serving sizes.Drug and Alcohol Dependence, 208, 107843. https://doi.org/10.1016/j.drugalcdep.2020.107843
Goodman, S., Leos-Toro, C., & Hammond, D. (2020). Risk perceptions of cannabis- vs. alcohol-impaired driving among Canadian young people.Drugs: Education, Prevention and Policy, 27(3), 205–212. https://doi.org/10.1080/09687637.2019.1611738
Goodman, S., Wadsworth, E., Leos-Toro, C., & Hammond, D. (2020). Prevalence and forms of cannabis use in legal vs. Illegal recreational cannabis markets.The International Journal on Drug Policy, 76, 102658. https://doi.org/10.1016/j.drugpo.2019.102658
Wadsworth, E., Leos-Toro, C., & Hammond, D. (2020). Mental Health and Medical Cannabis Use among Youth and Young Adults in Canada.Substance Use & Misuse, 55(4), 582–589. https://doi.org/10.1080/10826084.2019.1691594
Goodman, S., Leos-Toro, C., & Hammond, D. (2019). Methods to Assess Cannabis Consumption in Population Surveys: Results of Cognitive Interviewing.Qualitative Health Research, 29(10), 1474–1482. https://doi.org/10.1177/1049732318820523
Goodman, S., Leos-Toro, C., & Hammond, D. (2019). The impact of plain packaging and health warnings on consumer appeal of cannabis products.Drug and Alcohol Dependence, 205, 107633. https://doi.org/10.1016/j.drugalcdep.2019.107633
Leos-Toro, C., Fong, G. T., Meyer, S. B., & Hammond, D. (2019). Perceptions of effectiveness and believability of pictorial and text-only health warning labels for cannabis products among Canadian youth.The International Journal on Drug Policy, 73, 24–31. https://doi.org/10.1016/j.drugpo.2019.07.001
Leos-Toro, C., Rynard, V., Murnaghan, D., MacDonald, J.‑A., & Hammond, D. (2019). Trends in cannabis use over time among Canadian youth: 2004-2014.Preventive Medicine, 118, 30–37. https://doi.org/10.1016/j.ypmed.2018.10.002
Leos-Toro, C., Rynard, V., & Hammond, D. (2018). Prevalence of problematic cannabis use in Canada: Cross-sectional findings from the 2013 Canadian Tobacco, Alcohol and Drugs Survey.Canadian Journal of Public Health = Revue Canadienne De Sante Publique, 108(5-6), e516-e522. https://doi.org/10.17269/CJPH.108.5955
Leos-Toro, C., Shiplo, S., & Hammond, D. (2018). Perceived support for medical cannabis use among approved medical cannabis users in Canada.Drug and Alcohol Review, 37(5), 627–636. https://doi.org/10.1111/dar.12823
Maynard, M., Andrade, L., Packull-McCormick, S., Perlman, C. M., Leos-Toro, C., & Kirkpatrick, S. I. (2018). Food Insecurity and Mental Health among Females in High-Income Countries.International Journal of Environmental Research and Public Health, 15(7). https://doi.org/10.3390/ijerph15071424
Minaker, L. M., Bonham, A., Elton-Marshall, T., Leos-Toro, C., Wild, T. C., & Hammond, D. (2017). Under the influence: Examination of prevalence and correlates of alcohol and marijuana consumption in relation to youth driving and passenger behaviours in Canada. A cross-sectional study.CMAJ Open, 5(2), E386-E394. https://doi.org/10.9778/cmajo.20160168
Leos-Toro, C., Hammond, D., & Manske, S. (2015). A cross-sectional examination of medicinal substance abuse and use of nonmedicinal substances among Canadian youth: Findings from the 2012-2013 Youth Smoking Survey.CMAJ Open, 3(4), E387-94. https://doi.org/10.9778/cmajo.20140094
Conference Presentations
Leos-Toro C, Turgeon A. (2026, July) A National Framework for Safe, Equitable, and Responsible AI in Mental Health and Substance Use Care. AI for Public Health Symposium. Montreal, Canada.
Leos-Toro C, Fong GT, Hammond D. (2019, October) The efficacy of health warnings and package branding on perceptions of cannabis products among youth and young adults. Lisbon Addictions, Lisbon, Portugal.
Leos-Toro C, Meyer SB, Fong GT, Hammond D. (2019, October) Cannabis health knowledge and risk perceptions among Canadian youth and young adults. Lisbon Addictions, Lisbon, Portugal.
Leos-Toro C, Meyer SB, Fong GT, Hammond D. (2019, October) Comprehension of cannabis constituent labelling and successful functional tasks among Canadian youth and young adults. Lisbon Addictions, Lisbon, Portugal.
Leos-Toro C, Meyer SB, Fong GT, Hammond D. (2019, October) Perceptions of effectiveness and believability of pictorial vs text-only health warning labels for cannabis products. Lisbon Addictions, Lisbon, Portugal.
Goodman S, Leos-ToroC, Hammond D. (2019, October) The impact of plain packaging and health warnings on consumer appeal of cannabis products. Lisbon Addictions, Lisbon, Portugal.
Leos-Toro C & Hammond D. (2018, May) The efficacy of health warnings and package branding on perceptions of cannabis products among youth and young adults. International Society for the Study of Drug Policy, Vancouver, BC, Canada.
Goodman S, Leos-Toro C, Hammond D. (2018, May) Cannabis-impaired driving and perceptions among Canadian youth and young adults. International Society for the Study of Drug Policy, Vancouver, BC, Canada.
Hammond D, Goodman S, Leos-Toro C. (2018, May) Measuring cannabis consumption purchase price, & purchase sources: Implications for evaluating cannabis legalization. International Society for the Study of Drug Policy, Vancouver, BC, Canada.
Leos-Toro C, Shiplo S, Hammond D (2017, November). Perceived stigma among approved medical cannabis users in Canada. Canadian Centre on Substance Use and Addictions: Issues of Substance, Calgary, AB, Canada.
Leos-Toro C, Shiplo S, Hammond D (2017, May). Perceived stigma among approved medical cannabis users in Canada. Harm Reduction International, Montreal, QC, Canada.
Leos-Toro C, Rynard V, Hammond D (2017, May). Prevalence of problematic cannabis use in Canada: cross-sectional findings from the 2013 Canadian Tobacco, Alcohol, and Drugs Survey. Harm Reduction International, Montreal, QC, Canada.
Leos-Toro C, Hammond D. (2014, April). Controlled Substance Use Among Canadian Youth. Paper presented at Annual University of Waterloo Applied Health Science’s Graduate Student Research Conference, Waterloo, ON, Canada.
GRANTS
Canadian Centre on Substance Use and Addiction
2020-2022
Health warnings, product labelling regulations, and consumer understanding of the health risks of cannabis. Closing the Gaps in Cannabis Research. [$86,306 CAD]
Goodman S, Hammond D, Leos-Toro C.
Canadian Institutes of Health Research Project Grant
2018-2023
Marijuana legalization policy: Impact on prevalence and risk behaviours among youth and young adults in Canada. [$1,514,700 CAD]
Hammond D, Hall W, Pacula R, George T, Rehm J, Werb D, Boudreau C, Leos-Toro C, Wadsworth E, Porath A, Elliot R.
INTERNATIONAL CANNABIS POLICY STUDY
In 2018, Canada became the second country to legalize recreational cannabis use. The current study will examine the impact of cannabis legalization on Canadian youth and young adults. The study will examine the extent to which legalization is associated with changes in five primary outcomes: 1) the prevalence and patterns of cannabis use, including use among 'minors'; 2) risk behaviours, including driving after cannabis use; and 3) the commercial retail environment, including the price and the type of products used; 4) perceptions of risk and social norms; and 5) the effectiveness of specific regulatory policies, including advertising restrictions, product labelling and warnings, public education campaigns, and the use of cannabis in public spaces and workplaces. The proposed study consists of a quasi-experimental design with prospective cohort surveys conducted in Canada, as well as in two 'control' jurisdictions: US states where recreational cannabis use remains illegal ('US Illegal' states), and US states where recreational cannabis use has been legalized ('US Legal' states). A cohort of youth and young adults (aged 16 to 30) will be recruited at 'baseline'- prior to the implementation of legalization in Canada- and at 12-, 24-, and 36-month 'post-implementation'. Representative samples will be recruited from each of three study conditions: Canada (n=10,000; 1,000 in each province), 'US Illegal' states (n=10,000), and 'US Legal' states (n=10,000). Analyses will examine national-level changes in Canada over time compared to 'US Legal' and 'US Illegal' states, as well as between provinces to examine differences in policy implementation. Overall, the proposed research will provide a rigorous design for evaluating the impact of national-level cannabis legislation in Canada using 'within-country' and 'between-country' controls over time. This time-sensitive research is urgently needed to inform future policy in Canada and internationally.
2017-2018
Marijuana legalization: Impact on prevalence and risk behaviours among youth and young adults in Canada. [$100,000 CAD]
Hammond D, Hall W, Pacula R, George T, Rehm J, Werb D, Boudreau C, Leos-Toro C, Wadsworth E, Porath A, Elliot R.
In 2018, Canada will become the second country to legalize recreational cannabis use. The current study will examine the impact of cannabis legalization on Canadian youth and young adults. The study will examine the extent to which legalization is associated with changes in five primary outcomes: 1) the prevalence and patterns of cannabis use, including use among 'minors'; 2) risk behaviours, including driving after cannabis use; and 3) the commercial retail environment, including the price and the type of products used; 4) perceptions of risk and social norms; and 5) the effectiveness of specific regulatory policies, including consumer awareness and knowledge of health warnings, exposure to cannabis marketing, exposure to public education campaigns, and use of cannabis in public spaces and workplaces. The proposed study consists of a quasi-experimental design with prospective cohort surveys conducted in Canada, as well as in two 'control' jurisdictions: US states where recreational cannabis use remains illegal ('US Illegal' states), and US states where recreational cannabis use has been legalized ('US Legal' states). A cohort of youth and young adults (aged 16 to 24) will be recruited at 'baseline'- prior to the implementation of legalization in Canada- and at 12-, 24-, and 36-month 'follow-up' in three conditions: Canada (n=5,000), 'US Illegal' states (n=5,000), and 'US Legal' states (n=5,000). Participants will be recruited using face-to-face sampling and will complete online surveys. Postal code information will also be collected to examine the effect of geographic proximity to legal sales outlets in Canada after implementation. Overall, the proposed research will provide a rigorous design for evaluating the impact of national-level cannabis legislation in Canada using 'within-country' and 'between-country' controls over time. This time-sensitive research is urgently needed to inform future policy in Canada and similar initiatives in other countries.
MEDIA COVERAGE
Few consumers understand THC levels in cannabis edibles.EurekaAlert! February 9, 2020.
As many teens smoke tobacco as smoke pot, study finds.CBC News. May 9, 2017.
Canadian Teens Slightly Keener On Cannabis Than Tobacco: Report.Civilized. May 16, 2017.