Effects of Very Low Nicotine Content Cigarette use on Cigarette Reinforcement among Smokers with Serious Mental Illness.

BACKGROUND: Among people without psychiatric disorders who smoke, very low nicotine content (VLNC) cigarette use reduces cigarette reinforcement. Whether this is true of people with serious mental illness (SMI) who smoke is unknown. Using a hypothetical purchase task, we compared the effects of 6-week use of VLNC versus normal nicotine content (NNC) cigarettes on study cigarette and usual brand (UB) cigarette reinforcement among people with SMI who smoke. METHODS: After a baseline period of UB cigarette use, participants with SMI (n = 58) were randomized to use NNC cigarettes (15.8 mg nicotine/g tobacco) or VLNC cigarettes (0.4 mg/g) for 6 weeks. At Week 6, they completed the CPT for both their assigned study cigarette and UB. The groups were compared on demand intensity (number of cigarettes purchased at no cost) and elasticity (rate of decline in demand as price increases) using extra sum-of-squares F-tests. The effects of treatment on demand indices while controlling for covariates were assessed using hierarchical regression. RESULTS: At Week 6, intensity of demand for study cigarettes was lower and elasticity was higher for the VLNC group relative to the NNC group (p < 0.0001). Furthermore, intensity of demand for UB cigarettes was lower for participants in the VLNC group relative to participants in the NNC group (p < 0.01). When controlling for baseline cigarettes per day, intensity remained significantly different for study cigarettes and usual brand cigarettes at Week 6. CONCLUSION: A nicotine reduction policy may reduce cigarette reinforcement in this vulnerable population.

Mediational pathways of tobacco use among adult daily smokers with psychiatric symptoms in the Population Assessment of Tobacco and Health (PATH) survey.

INTRODUCTION: Individuals with psychiatric conditions suffer disproportionately from tobacco-related morbidity and mortality, but the factors driving this relationship remain unclear. We used data from the Population Assessment of Tobacco and Health (PATH) to investigate whether associations between internalizing psychiatric symptoms and change in smoking heaviness (as measured by cigarettes per day (CPD) were mediated by self-reported respiratory symptoms, smoking risk perceptions, and cigarette dependence. METHODS: This study used data from PATH Waves 1 through 4 (2013-2017, n = 4,152). Psychiatric symptoms were indexed with the internalizing sub-scale of the Global Appraisal of Individual Needs-Short Screener (GAIN-SS) among daily smokers. We fit auto-regressive structural equation models (SEM) to data from Wave 1-3 and 2-4 to determine the direct and indirect associations between internalizing symptom scores and CPD through each mediator. RESULTS: The association between internalizing symptoms and CPD was mediated by cigarette dependence (indirect: B = 0.004, SE = 0.041, p = 0.023) and respiratory symptom severity (indirect: B = 0.018, SE = 0.097, p < 0.001). Internalizing symptoms predicted higher harm perceptions (B = 0.056, SE = 0.035, p < 0.001) but the indirect relationship with CPD was non-significant. Findings from Waves 2-4 replicated these results. CONCLUSION: Our results indicate that cigarette dependence and respiratory symptom severity partially mediate the relationship between internalizing symptoms and CPD but risk perceptions were not significant predictors in our models. This suggests that efforts to reduce smoking among people with internalizing disorders should focus on decreasing nicotine dependence and increasing awareness of respiratory symptoms to encourage a quit attempt or switch to a less harmful source of nicotine.