The aim of this proposal is to accurately assess the effects of TNP on MJ withdrawal symptoms across 15 days of biochemically confirmed MJ abstinence using a placebo-controlled, double-blind, randomly assigned treatment design, while closely monitoring any potential adverse effects, including changes in nicotine use and dependence.

To achieve these goals, 116 carefully screened cannabis-dependent individuals (58 female) will be randomly assigned to one of two doses (0 mg or 7mg nicotine) of TNP (transdermal nicotine patch) while they abstain from MJ for 15 days. Subjects will be administered a follow-up phone interview 30 days after the termination of treatment to assess the effects of nicotine-patch treatment on: 1) frequency of nicotine and tobacco smoking intake, 2) Fagerstrom Test of Nicotine Dependence (FTND)-assessed nicotine dependence, 3) new use of nicotine during the time since completion of the study, and 4) marijuana and other drug use patterns. Large financial contingencies will be used to provide a high degree of abstinence and study completion. This will be the first adequately powered study to assess the effects of TNP on MJ negative affect-related withdrawal symptoms and urges to use MJ. Withdrawal patterns and abstinence will be assessed in two groups of MJ-dependent individuals: 1) those who rarely or never smoke tobacco, and 2) those who smoke four or fewer tobacco cigarettes per day (very-light tobacco smokers). A stratified randomization method will be used to control for gender and tobacco-smoker status. It is hypothesized that MJ withdrawal symptoms will be less severe in the group assigned to the 7 mg patch than in the group assigned to the placebo. It is also hypothesized that individuals high in anxiety/neuroticism and those high in aggression/hostility will exhibit greater benefits from TNP than those low in these traits. Given that no gender differences were observed in our preliminary study, gender differences are not predicted. The over-the-counter availability, minimal abuse risks, and minimal adverse side-effects associated with TNP would make it an ideal and highly implementable treatment for MJ dependence if it can be demonstrated to be efficacious in reducing MJ withdrawal symptoms.