The Relationship between Cannabis Use and Demand for Cigarettes in Adolescents who Smoke Cigarettes.

Abstract

Rates of cannabis and tobacco co-use continue to increase among adolescents, but the behavioral mechanisms underlying co-use patterns are not well understood. The study goal was to assess the reinforcing effects (rewards) of cigarettes (behavioral economic demand) and sensitivity to immediate rewards (delay discounting) by cannabis use status. Participants (N = 70, ages 17-19 and reported smoking at least 1 cigarette per day for the past 6 months) completed a timeline follow-back interview assessing past 30-day cannabis use; a Cigarette Purchase Task (how many cigarettes would purchase in a 24-hour period across range of prices per cigarette) assessing five cigarette demand indices; and a Delay Discounting Task assessing the tendency to choose smaller, sooner rewards over larger, later rewards. Participants were categorized into three cannabis use groups (daily, non-daily, non-use). We compared the three cannabis use group curves across the two parameters of the exponentiated demand equation, and delay discounting was analyzed using area under the curve. Cigarette demand intensity was significantly higher among those who reported daily cannabis use than those who do not use. Additionally, those who used cannabis daily were more sensitive to changes in cigarette price (alpha) than those who used non-daily and did not use cannabis. We found no differences in delay discounting by cannabis use status. Among adolescents who smoke cigarettes daily, those who also use cannabis daily reported greater cigarette demand than those who do not use cannabis. However, adolescents who smoke cannabis daily were more sensitive to price, suggesting less persistence of purchasing in the face of higher prices.