Associations of multiplicity of comorbid health conditions, serious mental illness, and health care costs.

Using a nationally representative U.S. sample, this study analyzed the effects of serious mental illness (SMI) and comorbid medical conditions on the cost of health care. The results of path model indicated that SMI and comorbid health conditions each increased total health care costs. Additionally, individuals with SMI were likely to have more comorbid medical conditions, which in turn, increased total health care costs. Findings raise awareness of an increased risk of medical conditions among individuals with SMI and the concern of high expenditures associated with comorbid SMI and medical conditions.