Objective: The current study examined longitudinal associations between friend's substance use, friendship quality, parent-adolescent relationship quality, and subsequent substance use among an adult population. Design: Participants were 166 adolescents, their parents, and their close same-sex friends recruited from both urban and suburban high schools surrounding a large metropolitan area. Measures of relationship characteristics in the10th grade were used to predict concurrent substance use and changes in substance use over a 1-year period. Results: The most consistent predictor of the use of different substances and changes in substance use over time was the friend's substance-using behavior. Negative interpersonal interactions with a friend were related only to tobacco use, and friendship support neither contributed to nor protected against substance use. Mother-adolescent relationship support was associated with lower levels of concurrent substance use, as well as lower levels of hard drug use over time. Conclusions: Findings highlight the need to examine parents and peers simultaneously and the importance of parental relationships and peer behavior on adolescent substance use. Limitations and future directions are discussed.

Objectives: The time to first cigarette (TTFC) of the day has been identified as the best single-item indicator of nicotine dependence. However, TTFC has not been extensively used in clinical settings and is not a criterion for tobacco use disorder, perhaps due to a lack of information about TTFC's predictive value. This review provides a synthesis of the accumulating literature on TTFC's relationships with nicotine dependence, identify gaps, and inform future clinical and epidemiologic research of potential uses of TTFC. Methods: A systematic review of the literature was conducted using PubMed, Google Scholar, and Web of Science ISI databases. We identified 16 articles examining the relation between TTFC and negative outcomes associated with high levels of nicotine addiction and Tobacco Use Disorders (eg, high levels of nicotine and toxicant exposure, progressive use over time, failed cessation, head-and-neck cancers). Results: Earlier TTFC was consistently associated with greater likelihood of cessation failure and relapse, and higher levels of biomarkers of tobacco exposure. Several of these associations were found among both adult and adolescent smokers, and remained even after accounting for smoking behaviors (eg, cigarettes/day). Conclusions: Earlier TTFC is a key indicator of greater nicotine dependence. Knowledge of a smoker's TTFC may allow clinicians to accurately inform smokers of health risks and assign greater resources during cessation attempts. Smokers may be able to use TTFC to self-select cessation aids and accurately assess their unique smoking-related health risks. TTFC may be a better item than cigarettes/day for accurately quantifying dependence and risk in epidemiologic studies.

Introduction: Sleep disruption is common among smokers, however, extant studies primarily explore differences between smokers and non-smokers. The time to smokers’ first cigarette of the day (TTFC) after waking, a strong indicator of addiction severity, is inversely associated with numerous health outcomes. The present study tests the hypotheses that, in a representative sample of daily smokers, the severity of nicotine addiction is associated with shorter habitual sleep duration and excessive daytime sleepiness. Methods: We examined the associations between TTFC and sleep outcomes (sleep duration and daytime excessive sleepiness), and the mediating effects of specific sleep disruption pathways (delayed sleep onset, awakenings at night, early awakening) using structural equation modeling. Analyses included cross-sectional data from 2,015 current daily smokers aged 16-85 years who participate in the 2005-06 and 2007-08 National Health and Nutrition Examination Survey (NHANES). Results: Among daily smokers, earlier TTFC was associated with both shorter sleep duration and excessive daytime sleepiness (p’s < .001, R2’s = .15, .29, respectively). Of sleep disruption pathways, only early awakening mediated the associations of TTFC with both outcomes (sleep duration: b = .02, 95% CI: .006, 042; daytime sleepiness: b = -.01, 95% CI: -.03, -.004), even after controlling for variables confounded with smoking status and sleep outcomes. Conclusions: Findings suggest that early awakening may be the mechanism responsible for the association between nicotine addiction severity and poor sleep outcomes of shorter sleep duration and excessive daytime sleepiness. These data may inform cessation strategies, risk assessment and future longitudinal studies on the relations between sleep and nicotine addiction. Implications: Smokers have impaired sleep quality and quantity as compared to non-smokers; however, that severity of nicotine addiction is an important factor in sleep quality, not just smoking status. Higher levels of addiction leads to less sleep and more daytime sleepiness. The relation between addiction severity and sleep is mediated by waking too early in the morning, and not by difficulty falling asleep or waking during the night. These findings could play an important role in supplementing cessation efforts; sleep disruption may interact with other negative physiological and emotional symptoms related to nicotine withdrawal and could result in more cessation failure.