Cannabis and Tobacco Use Among Young People and Labor Market Outcomes in Midlife: A 23-Year Population-Based Longitudinal Study.

Objective: Research suggests an association between cannabis use and adverse labor market outcomes, but the mechanisms are unknown. We studied the nature of this association by comparing the relative roles of cannabis and tobacco use in predicting midlife outcomes.

Method: We analyzed data from the Young in Norway Study, a 23-year longitudinal investigation ( = 2,550; 56% female). Cannabis and tobacco use, potential confounders, and mediators were assessed by self-report. We used register data on income, years Not in Education, Employment or Training (NEET), and welfare benefits.

Results: We compared cannabis users (7%) and regular tobacco users (15%) with nonusers. After confounders were controlled for, cannabis users had lower income (income decile difference = -1.31; 95% CI [-1.83, -0.80]), had more NEET years (incidence rate ratio [IRR] = 1.87; 95% CI [1.34, 2.61]), and received welfare benefits more often (odds ratio [OR] = 2.84; 95 % CI [1.56, 5.17]). Tobacco users also earned less (income decile difference = -0.51; 95% CI [-0.86, -0.17]) and received welfare benefits more often (OR = 1.74; 95 % CI [1.14, 2.66]) but did not have more NEET years (IRR = 1.22; 95% CI [0.94, 1.59]). The reduction when controlling for confounders was larger for tobacco than for cannabis. Including mediators further reduced the associations for tobacco use considerably, whereas only slight reductions were observed for cannabis.

Conclusions: The robust associations of cannabis use with poor labor market outcomes, even after adjustments, seem to differ from how tobacco use is related to such outcomes. More knowledge is needed about causal effects of cannabis use on important life domains.