Discrimination and insomnia: Examining depressive symptoms and nicotine withdrawal through a serial mediation model in a sample of smokers.

Insomnia is a common sleep disorder associated with poor health outcomes. Individuals from racially underrepresented groups as well as women tend to report more severe insomnia symptoms, and frequent experiences of discrimination have been found to drive such disparities. Smokers commonly experience sleep problems since nicotine can alter the sleep-wake cycle. Discrimination is associated with increased nicotine dependence, and such discrimination may also intensify tobacco withdrawal, specifically mood and cognitive-related aspects of withdrawal. The potential impact of discrimination on withdrawal symptoms and related mood symptoms like depression may lead to increases in insomnia symptoms. However, no studies to date have evaluated the indirect association of discrimination with insomnia severity through nicotine withdrawal and depressive symptoms. Therefore, this cross-sectional survey of n = 110 non-Hispanic Black and White current smokers (48.2 % Black, 69.1 % women) investigated these associations through a serial mediation model. Controlling for race, gender, nicotine dependence levels, and income, multivariate analyses supported a significant indirect effect of discrimination on insomnia severity through depressive symptoms. Analyses supported the hypothesized serial mediation model whereby discrimination is positively associated with depressive symptoms, which in turn are linked to more severe nicotine withdrawal, leading to greater insomnia severity. Smokers encountering frequent experiences of discrimination might be at increased risk of suffering insomnia as a result of their increased depressive and withdrawal symptoms. Future work is necessary to understand the role of depressive symptoms in these associations as well as possible implications for smoking relapse and success of smoking cessation programs.