Utilization of public mental health services by adults with serious mental illness.

Public mental health (MH) services were examined for non-elderly adults with serious mental illness (SMI) using a database combining information from Medicaid, MH, and substance abuse agencies in three states. These data show that between 23% and 39% of those with SMI received MH services only through Medicaid. Relative use of community versus state hospitals for delivery of psychiatric inpatient care varied across the three states. However, state hospitals accounted for a large proportion of total inpatient days, due to high mean annual days of care. In two states, Medicaid paid for fewer psychiatric inpatient days than expected.