Crossed Pathways: Tobacco–Cannabis Co‐Use and Motivation to Quit in Young Adults in France

INTRODUCTION: Among young adults, intertwined tobacco and cannabis use is a major concern, being linked to poorer cessation outcomes than exclusive use. However, little is known about the shared and simultaneous determinants of motivation to quit both substances, and how the use of one influences readiness to quit the other. We aimed to examine these relationships, focusing particularly on the role of low socioeconomic status. METHODS: In a cross-sectional survey of French young adults (18-30 years) who co-use tobacco and cannabis, we modelled pathways to readiness to quit both substances using generalised structural equation modelling (GSEM). Factors associated with four or more lifetime quit attempts for tobacco and cannabis were also assessed using separate binary logistic regressions. RESULTS: Among 357 participants (54.9% male), GSEM analysis revealed that low socioeconomic status was positively associated with frequency of use (β = 0.12, 95% confidence interval [0.04; 0.19] for tobacco; 0.09 [0.02; 0.17] for cannabis) and directly linked to greater readiness to quit both substances (β = 0.14 [0.04; 0.24] for tobacco; 0.13 [0.03; 0.23] for cannabis). Further regression analyses suggested that financial strain was the primary driver of these two latter associations with readiness to quit. For both substances, ≥ 4 lifetime quit attempts were associated with material deprivation (adjusted odds ratio 1.39 [1.22; 1.58] for tobacco; 1.24 [1.10; 1.40] for cannabis). DISCUSSION AND CONCLUSIONS: In young adults who co-use tobacco and cannabis, financial strain emerged as a common determinant of motivation to quit, supporting the potential utility of monetary incentives in dual cessation. Further research, including qualitative studies, is needed to clarify cross-substance effects.