BACKGROUND AND AIMS: Although many people who use cannabis report mood-enhancing effects, affective responses are thought to vary within and between individuals. This study examined the bidirectional associations between momentary affect and cannabis use and the potential moderating role of emotion regulation in this.

DESIGN: Intensive longitudinal observational study using experience sampling method (ESM).

SETTING: Denmark.

PARTICIPANTS: Adults in Denmark who use cannabis near daily (n = 113; Age: mean = 31.57 years, median = 29 years, standard deviation = 10.28, inter-quartile range = 23-36; 60.2% male).

METHOD AND MEASUREMENTS: Participants completed a baseline survey (substance use and emotion regulation difficulties) and 21 days of experience sampling (three assessments daily; affect and use). We used multilevel models to assess: (1) the associations between positive affect (PA) and negative affect (NA) and subsequent cannabis use, (2) whether cannabis use predicted changes in affect shortly after use (at the same assessment) and (3) whether cannabis use predicted changes in affect at a later moment (at the next assessment). Next, we assessed whether emotion regulation difficulties moderated associations tested in models 1 and 2.

FINDINGS: Higher PA predicted a greater likelihood of cannabis use before the next assessment [odds ratio (OR) = 1.05, 95% confidence interval (CI) = 1.01-1.09], and cannabis use predicted increased PA at the same assessment (b = 0.59, 95% CI = 0.27-0.92), but not at the next assessment. NA was not related to use or vice versa at group level. Emotion regulation difficulties did not statistically significantly moderate the associations between PA or NA and subsequent cannabis use; however, emotion regulation difficulties moderated short-term effects of cannabis use on NA (b = -0.014, 95% CI = -0.027 to -0.002), with individuals with higher emotion regulation difficulties showing lower NA shortly after use compared with non-use moments.

CONCLUSIONS: Within individuals who use cannabis near daily, relatively higher momentary positive affect, but not negative affect, appears to precede and follow cannabis use. Cannabis use appears to be associated with higher positive effect at the time of assessment but does not predict positive affect hours later. Individuals with greater emotion regulation difficulties may experience short-term reductions in negative effect after cannabis use.