How has cannabis use changed in Canada since legalization?

Past-3-month cannabis use increased from 14.0% (2018) to 17.5% (2019) to 20.0% (2020). Daily or almost daily use rose to 7.9%. Female use rates rose to equal male rates for the first time. Use increased particularly among adults 25+ and in some provinces. Legal sourcing increased while reliance on friends, family, and illegal sources decreased.

Analysis of three quarters of the National Cannabis Survey: Q1 2018 (pre-legalization), Q1 2019 (post-legalization year 1), and Q4 2020 (two years post, also post-edible legalization). Nationally representative survey data.

This is the most comprehensive look at how Canadian cannabis use actually changed after legalization. The shift from illegal to legal sources suggests the policy is achieving one key goal, while the overall increase in use raises ongoing public health questions.

The convergence of male and female use rates post-legalization is notable. It suggests that prohibition may have disproportionately deterred women from using cannabis, and that normalization has equalized access. Whether this equalization carries public health implications requires ongoing monitoring.

Cannot disentangle legalization effects from COVID-19 effects on 2020 data. Self-reported use may be subject to social desirability bias. Response rates and representativeness may shift over time.