The "new homeless" of the eighties and nineties are not only more numerous; they are younger, more likely to use drugs, and they exhibit symptoms of mental illness. Homeless mentally ill individuals typically have estranged family relationships and fewer supportive relationships compared with other homeless persons. They typically have more negative family experiences and feelings of detachment from family. The implications for the utilization of the Adult Attachment Interview as a foundation from which to draw clinically relevant information with homeless and runaway youth may have an impact on future treatment and research. Psychologists can contribute to the treatment of homeless and runaway youth through clinical work involving long-term treatment using knowledge of attachment theory and research. (Contains 47 references.) (Author/JDM)