Psychotic disorders among homeless subjects attending a psychiatric emergency service

Homelessness is an increasing problem among subjects with severe mental illnesses and little is known about the characteristics of homeless subjects with psychosis using emergency psychiatric services. The aims of the present study were to assess the frequency of psychotic disorders among subjects attending a psychiatric emergency service and to explore the clinical and demographic characteristics of these subjects and the management proposed by the emergency staff.

All homeless patients (n=104) consecutively attending a psychiatric emergency service were included over a 6-month period. Patients were categorised according to ICD-10 diagnoses as presenting with psychotic disorder (schizophrenia and other non-affective psychotic disorders) versus other disorders. A random sample of matched non-homeless controls (n=71) was included over the same period.

Nearly one out of three homeless subjects (32.7%) presented with a psychotic disorder, a higher proportion than that found in non-homeless subjects (15.7%). Compared to non-homeless subjects with psychosis, homeless subjects with psychosis were more likely to be male and to present with drug use disorder. The likelihood of being hospitalised after attending the psychiatric emergency services did not significantly differ between the two groups. Compared to homeless subjects with other psychiatric disorders, homeless subjects with psychosis were more likely to be single, to have a history of psychiatric hospitalisation and presented less frequently with anxiety or depressive symptoms motivating admission.

Most homeless subjects with psychosis attending a psychiatric emergency service were already identified as suffering from a severe mental illness, suggesting that homelessness was a consequence of a break in contact with mental health services. Since homelessness is incompatible with the adequate management of psychosis, strategies have to be developed in mental health organisations in combination with outside partnerships, to drastically reduce the frequency of this condition in subjects with psychosis.