[Evidence-based treatment of mentally ill homeless persons].

A systematic review of the literature shows that it is possible to reduce homelessness among mentally ill homeless persons, partly by offering access to housing and partly by providing intensive care through Assertive Community Treatment. Assertive Community Treatment can, to some extent, decrease psychiatric symptoms and increase quality of life. It is evident that by offering housing, homelessness may be reduced, but the comparison of independent housing and group living did not reveal big differences.