Serious Mental Illness (SMI)

Serious mental illness (SMI) are long-term mental, behavioral, or emotional disorders that significantly impair the ability to function and limit or interfere with life activities. SMIs include psychotic disorders, bipolar disorder, major depression with psychotic symptoms, treatment-resistant depression (TRD), anxiety disorders, eating disorders, and personality disorders (PDs). SMIs require social supports and psychiatric hospitalizations and can lead to homelessness, incarceration, and coexisting substance use disorders (SUDs). SMIs are:

• Common with a high degree of morbidity (illness): 4%-6% of U.S. adult population or about 11 million adults.
• Frequently under-/misdiagnosed or under- or not treated. A 2008 study found 60% of adults with an SMI had used mental health services. Only 40% used any outpatient health care services.
• Cause disparities in healthcare compared with populations with non-SMI mental health diagnoses. Disparities are more pronounced in groups including minorities, economic disadvantage, rural residents, LGBTQ+, and non-English speakers.