"These findings highlight the importance of smoking cessation among this vulnerable population," says Anne Thorndike, MD, MPH, of the MGH Department of Medicine, lead and corresponding author of the report. "But they also indicate that continued weight gain associated with tobacco cessation is likely to contribute to a rise in the already high rates of obesity,diabetes and hypertension among people with serious mental illness."
An increased risk of cardiovascular disease is a primary cause of the greatly reduced life expectancy - up to 25 years less than the general population - among those with serious mental illness. Both obesity and smoking are at least twice as high among adults with mental illness, and other risk factors such as hypertension, diabetes and elevated cholesterol levels are also more common. While a 2013 study led by another MGH research team found that the health benefits of quitting smoking were not eliminated by resultant weight gain, participants in that study did not have mental illness, were not obese and had low levels of other risk factors prior to smoking cessation. The authors of the current study also note that most smoking cessation trials have excluded patients with serious mental illness, leaving open the question of whether they would share the benefits seen in the general population.