Cannabis Users Had Worse Tobacco Withdrawal in the First Week of Quitting

Among 330 participants with verified tobacco abstinence from a cessation trial (55 cannabis co-users, 275 tobacco-only), cannabis co-users had significantly elevated withdrawal scores at week 1 (mean 9.3 vs 7.1, p < 0.01). No differences were found at weeks 4, 8, or 11. The effect was significant after controlling for age, treatment arm, and site.

Secondary analysis of a multi-site double-blind clinical trial for tobacco cessation. Participants were randomized to placebo, nicotine patch, or varenicline and followed for 11 weeks. Cannabis co-use was determined by urine toxicology. Analysis focused on 330 participants with biochemically verified 7-day abstinence, comparing withdrawal trajectories using the Minnesota Nicotine Withdrawal Scale (MNWS) at baseline and weeks 1, 4, 8, and 11.

About 30% of tobacco users also use cannabis, and this population has greater difficulty quitting tobacco. This study identifies a specific mechanism: worse withdrawal in the critical first week. This is actionable information for designing cessation interventions that provide extra support during the initial quit period for co-users.

The first week of tobacco cessation is when relapse risk is highest. The finding that cannabis co-use amplifies withdrawal specifically during this critical window helps explain why co-users have lower quit rates and suggests that targeted interventions during week 1 could improve outcomes.

Secondary analysis. Cannabis use classified by single urine screen rather than quantified use patterns. Only included participants who achieved abstinence, so cannot comment on those who relapsed. Co-use group was relatively small (N=55). Cannot determine whether cannabis use worsened withdrawal or whether shared vulnerability drives both.