What are the two main reasons why persons with serious mental illness (SMI) die 10 to 20 years earlier than the general population, as described in the chapter?

The text lists two main reasons: part of the earlier death is attributed to suicide and injury, and the other contributing factor is the strong association among serious mental illness, chronic disease, and substance use.

According to the chapter, persons diagnosed with serious mental illness die 10 to 20 years earlier than the general population. The first stated reason is suicide and injury. The second stated reason is the strong association among serious mental illness, chronic disease, and substance use. The text adds that people with serious mental illness are less likely to receive preventive screening and interventions, less likely to receive treatment for diagnosed comorbidities, and more likely not to adhere to medical interventions, which exacerbates the mortality disparity.