Rates of tobacco smoking are very high in people with serious mental illness (SMI), and this is an important contributor to the early mortality seen in this population. Smoking is also associated with worsening of cognitive functioning. Fortunately, research has repeatedly shown that treatments are effective in helping people with SMI quit smoking. These include both counseling interventions and smoking cessation medications. The same medications are effective as in other populations, though people with SMI can require multiple medications and treatment that is more intensive. As with other populations, the medication with the greatest efficacy appears to be varenicline. SAMHSA has published a guide for Implementing Tobacco Cessation for Individuals with Serious Mental Illness.