Evaluating nicotine craving, withdrawal, and substance use as mediators of smoking cessation in cocaine- and methamphetamine-dependent patients.
Smoking is highly prevalent in substance dependence, but smoking-cessation treatment (SCT) is more challenging in this population. To increase the success of smoking cessation services, it is important to understand potential therapeutic targets, like nicotine craving, that have meaningful but highly variable relationships with smoking outcomes. This secondary analysis of data from National Drug Abuse Treatment Clinical Trials Network protocol CTN-0046 (Smoking Cessation and Stimulant Treatment) characterized the presence, magnitude, and specificity of nicotine craving as a mediator of the relationship between SCT and smoking abstinence in the context of stimulant-dependence treatment. The original trial was a randomized, 10-week study conducted at 12 outpatient substance use disorder (SUD) treatment programs. Adults with cocaine and/or methamphetamine dependence (n=538) were randomized to SUD treatment as usual (TAU) or TAU+SCT. Participants reported nicotine craving, nicotine withdrawal symptoms, and substance use in the week following a uniform quit attempt of the TAU+SCT group, and self-reported smoking 7-day point prevalence abstinence (verified by carbon monoxide) at end-of-treatment.
Bootstrapped regression models indicated that, as expected, nicotine craving in the week following a quit attempt was a significant mediator between SCT and smoking abstinence, accounting for 14% of the total effect. Nicotine withdrawal symptoms and substance use were not significant mediators. This pattern held for separate examinations of cocaine and methamphetamine dependence.
Conclusions: Nicotine craving accounts for a small but meaningful portion of the relationship between smoking-cessation treatment and smoking-abstinence during SUD treatment. Nicotine craving, particularly during the week following a quit attempt, may be a useful therapeutic target for increasing the effectiveness of smoking-cessation treatment in substance dependence. This timing is useful for clinicians and researchers attempting to predict outcomes within SUD treatment, as the increased variability and intensity of craving after a quit attempt may produce a clearer relationship between craving and nicotine outcomes.
Related protocols: CTN-0046