Mental illness and substance use problems in relation to homelessness onset.

Objectives: The relationships among youth (≤ 24 years) versus adult (>24 years) homelessness onset, lifetime serious mental illness, and substance use problems is not well understood. We sought to explore these associations among 394 homeless adults, 124 of whom reported youth-onset homelessness.
Methods: Covariate-adjusted logistic regression analyses evaluated the associations among homelessness onset, serious mental illness, and self-reported substance use problems.
Results: Youth-onset homelessness was associated with greater likelihood of serious mental illness and sedative problems, and a lower likelihood of cocaine problems, in adjusted analyses (p values ≤ .04).
Conclusions: Serious mental illness and sedative problems may characterize homeless youth who are vulnerable to adulthood homelessness, although longitudinal cohort studies are needed to explicate temporal relations between variables.