Cigarette smoking continues to be the leading cause of preventable death in North America, and it accounts for more than one of every five deaths in the United States each year. Among other diseases, smoking has conclusively been shown to cause cancer, heart disease, stroke, and lung diseases in smokers and people exposed to second-hand smoke such as spouses, coworkers, and children. A smoker who does not quit has a 50% chance of dying from smoking (Fiore et al., 2008; U.S. Department of Health and Human Services [HHS], 2014).

Fortunately, quitting smoking helps at any age. Smokers who quit experience rapid improvements in their health, such as reduced risk for heart attack 1 year after quitting. Within 5 years of quitting, the risk of cardiovascular disease can fall to the same as that of a nonsmoker, and the chance of several smoking- caused cancers is cut in half (HHS, 2014). These statistics highlight the need for health professionals of all types to treat smoking aggressively.

Smoking is highly comorbid with mental health and substance use disorders (SUD), and people with these comorbidities are more likely to smoke, be heavier smokers, and die sooner from smoking-related illnesses than their peers (Centers for Disease Control and Prevention [CDC], 2013). Fortunately, many people with mental illness, SUD, or both want to quit smoking, and with evidence-based interventions and support, many are able to succeed without compromising other treatments. In this chapter, we describe the problem of smoking, its incidence and prevalence, major interventions, and the evidence base. We conclude by outlining future directions for improving outcomes.