Longitudinal examination of coping-motivated marijuana use and problematic outcomes among emerging adults

•Longitudinal analysis of coping-motivated marijuana use and related outcomes.•Changes in coping-motivated use were related to changes in marijuana use.•Changes in coping-motivated use were related to changes in marijuana problems. Cross-sectional research shows that coping-motivated marijuana use is associated with marijuana use and problems. However, limited research has examined how coping-motivated use might longitudinally relate to these outcomes. We examined the temporal relationship of coping-motivated marijuana use with severity of use and marijuana-related problems. Participants were 226 emerging adults, aged 18–25 years old, who currently used marijuana. Multilevel generalized linear models were used to evaluate the association between change in coping motives with change in frequency of marijuana use and marijuana problem severity from baseline to 6- and 12-month follow-ups. In the adjusted models, frequency of marijuana use was positively associated with between subject differences (IRR = 1.49; 95%CI: 1.30, 1.71; p