Published Thursday in the journal JAMA Network Open, the study found Canadians bought $1.86 billion more alcohol than expected based on pre-pandemic levels.
During the pandemic study period, mean monthly cannabis sales were more than $255 million — almost 25 per cent higher than the $205 million projected by researchers.
The number of cannabis stores in Hamilton also jumped from two in the first quarter of 2020 to 37 in the same period of 2021.
MacKillop believed the numbers reflect both an increase in personal use of cannabis and users shifting toward the legal cannabis market during COVID.
“I expected to see an increase, but 25 per cent above the predicted level is really high,” he said, noting in the last month of the research, June 2021, the legal cannabis market was more than $300 million monthly.