Objective: The study compared patterns of previous mental health servi
ce use among 100 homeless men with schizophrenia and 100 men with schi
zophrenia who had never been homeless and explored whether differences
in use of services were related to severity of illness. Methods: Subj
ects were recruited from shelters, clinics, and inpatient psychiatric
programs in New York City. Clinical interviewers used standardized res
earch instruments to collect data on psychiatric treatment history, me
ntal health service use within the past 12 months, adequacy of dischar
ge planning from the most recent psychiatric hospitalization, positive
and negative symptom levels, and presence of concurrent substance abu
se and antisocial personality disorder: Results and conclusions: Homel
ess subjects and never-homeless subjects had similar treatment histori
es and recent patterns of inpatient, outpatient, and emergency service
use. However, the homeless men were more likely to have been discharg
ed from their most recent psychiatric hospitalization against medical
advice and to have less adequate discharge planning for living arrange
ments, aftercare, and finances. Inadequacies in discharge planning wer
e most apparent among homeless men with triple disorders of schizophre
nia, substance abuse, and antisocial personality disorder.