Cannabis Co-Users Were Less Likely to Switch Away from Cigarettes

Participants who reported past-30-day cannabis co-use (N=56) smoked significantly more usual brand cigarettes during switch weeks than non-co-users (N=104, p=0.03) and were less likely to make a tobacco cessation attempt (p<0.05). This was true regardless of whether they were switching to very low nicotine cigarettes (VLNCs) or e-cigarettes.

Secondary analysis of a mixed-design study. Adult cigarette smokers not motivated to quit were assigned study products (VLNCs, e-cigarettes, or no product) for 4 weeks and asked to switch from usual cigarettes during specific weeks. Active nicotine vs placebo patches were provided double-blind.

Policies promoting switching from combustible cigarettes to reduced-harm alternatives (like e-cigarettes or VLNCs) may be less effective for cannabis co-users. Since about a third of the sample used both substances, this represents a substantial population that may need different tobacco cessation strategies.

Tobacco and cannabis are frequently co-used, and the smoking behaviors associated with each substance may reinforce each other. This study suggests that tobacco harm reduction strategies need to account for cannabis co-use, as people who use both substances may be more resistant to switching away from combustible cigarettes.

Secondary analysis not powered for this specific question. Small cannabis co-use subgroup (N=56). Self-reported cannabis use at baseline only. Cannot determine whether cannabis use directly caused resistance to switching or whether both behaviors share common underlying factors. Not generalizable to motivated quitters.