Mental health, alcohol and drug use, and criminal history among homeless adults.

As part of a community-based survey of 529 homeless adults, the authors analyzed factors associated with their use of mental health services. Homeless persons who had had a previous psychiatric hospitalization were the least likely to sleep in an emergency shelter, had been homeless nearly twice as long as the rest of the sample, had the worst mental health status, used alcohol and drugs the most, and were the most involved in criminal activities. The majority had not made an outpatient mental health visit in 5 years. It is suggested that diverse systems of care are needed for homeless persons.