There is a very high incidence of substance use and mental illness among the homeless population. In Santa Monica, 24% have co-occurring addiction and mental health issues. 56% have addictions but no mental health issues. 14% are mentally ill but do not suffer from addictions. Only 6% of the homeless population in Santa Monica is neither mentally ill nor addicted to drugs or alcohol.

Nationally, according to the National Alliance to End Homelessness, 45% of homeless individuals report mental illness within the past year, and 57% report a mental health problem at some time during their life. According to the U.S. Substance Abuse and Mental Health Services Administration, It is estimated that 20-25% of the homeless population has a serious mental illness, such as chronic depression, schizophrenia, bipolar disorder and severe personality disorders. For many homeless people, especially those living on the streets, these illnesses are untreated.

Drug and alcohol use is also common. At times this is a response to the mental health issue, and is an attempt to self-medicate. 46% of homeless individuals nationally reported alcohol use problems and 38% reported drug use problems in the past year.

The treatment needs of people with co-occurring mental health and substance use disorders is especially complex. Substance use can exacerbate or initiate a psychiatric disorder, can mask psychiatric symptoms, or cause symptoms that appear to be psychiatric. Behaviors related to mental illness can appear to be caused by substance use, and the use of substances may have a particularly strong effect on those living with mental illness. People with co-occurring disorders are especially vulnerable to becoming homeless. OPCC’s staff members and volunteers are adept at building trust with people with co-occurring disorders and helping them to address both of these issues.