BACKGROUND: Rates of cannabis use are rising, with potential public health implications. However, many people who use cannabis use it simultaneously with other psychoactive drugs such that their intoxicating effects overlap. Thus, it is important to understand cannabis use in the context of simultaneous use with other substances, especially in jurisdictions with legal access to cannabis. We used latent class analysis (LCA) to identify patterns of simultaneous use of cannabis with other drugs in a sample of Canadians who use cannabis and examined demographic and cannabis-related correlates of class membership.

METHOD: Data came from the 2023 Canadian Substance Use Survey. Individuals who reported past year cannabis use (N = 12,344) were included. Survey items asked participants if they combined cannabis with each of 10 different drugs over the past year, from which seven indicators of drug types used simultaneously with cannabis were derived for the LCA.

RESULTS: We identified three latent classes: 1) low overall simultaneous use with occasional simultaneous use of cannabis with alcohol, 2) simultaneous use of cannabis with alcohol and hallucinogens, and 3) high overall simultaneous use (i.e., simultaneous use of cannabis with alcohol, hallucinogens, illicit stimulants, and prescription drugs). Age, sex, income, and several cannabis-related variables (i.e., use frequency, medicinal use, problematic use) were uniquely associated with class membership.

CONCLUSIONS: Results illustrate distinct patterns of simultaneous use of cannabis with other drugs, which are linked with different levels of cannabis-related problems. Findings may inform education efforts on the risks associated with using cannabis simultaneously with various other drugs.