Increased cigarette craving following prior-day cannabis use among females who smoke combustible cigarettes

Objective: Nicotine-cannabis co-use among adults in the U.S. has become increasingly prevalent, but there is a lack of consensus on mechanisms of co-use. Inconsistent sex differences in nicotine-cannabis use have been documented in cross-sectional or longitudinal studies with sparse observations. There is a need for temporally-granular research to yield informative addiction prevention data. We examined the extent to which prior-day cannabis use is associated with cigarette craving on a given day and whether this association differs between sexes. Methods: In 2020–2022, 225 participants (Mage=43.06; 49.33 % female) completed 4-week Ecological Momentary Assessment (EMA), including measures of cannabis use captured at the end of the day and cigarette craving levels upon waking. Using a subsample of those reporting cannabis use on 1 + day during the EMA period (n = 101; Mage=42.94; 45.54 % female), we fitted multilevel models to investigate the effects of prior-day cannabis use on next-morning cigarette craving, adjusting for relevant covariates. Subsequently, we tested sex as the effect modifier. Results: In the main effect model, prior-day cannabis use was not associated with cigarette craving the next morning (b=0.05, p = .61). The interaction model revealed a significant interaction (b=-.44, p = .02) such that prior-day cannabis use was associated with elevated next-morning cigarette craving for females (b=.33; p = .03) but not for males (b=-.10; p = .36). Conclusions: Our findings show that prior-day cannabis use is differentially associated with cigarette craving between sexes (i.e., increased cigarette craving in females, but not males). Our study is among the first to demonstrate nuanced cross-level interactions in nicotine-cannabis co-use in ecologically-valid settings.