According to this hypothesis, a process occurs over a period of years spanning the entrance into adulthood and extending into their current situation. The interviews used a questionnaire of 100 items that covered characteristics, historical events, and current circumstances. Results revealed that the men were more involved in crime and alcohol abuse than were the women, but there were no sex differences in various mental health measures. When gender was held constant, similar patterns of crime, drug abuse, and mental illness were detected. Findings indicated that the "drift down" theoretical approach is useful for explaining why a significant number of persons are suffering on the streets. For many individuals, homelessness is a recent stage in a long-evolving series of afflictions that date back to childhood and is not the result of unique crises. Nevertheless, the majority of these homeless persons do not display the particular "drift down" patterns emphasized in this study. Results suggested that homelessness is more complicated than currently characterized by policymakers and scholars and that the inadequate response to the problem of homelessness results from diffuse and shortsighted policymaking. Tables and 35 references