Longitudinal Associations between Homelessness and Substance Use: Investigating Demographic Differences for Young Adults in Treatment.

Objective: To examine prospective, bidirectional associations between homelessness and substance use frequency among young adults receiving substance use treatment in the United States. We also investigated potential differences across demographic subgroups. Methods: Young adults (N = 3717, Mage = 20.1, 28% female, 7.3% sexual/gender minority, and 37% non-Hispanic White) receiving substance use treatment in the U.S. completed assessments at intake, 3 months, 6 months, and 12 months post-intake. Latent growth curve models with structured residuals (LGC-SR) were used to examine cross-lagged associations between homeless days and frequency of substance use and associated problems. Models were stratified by sex, race/ethnicity, and sexual and/or gender minority status. Results: Overall, days spent homeless (μslope= -0.19, p = 0.046) and substance use frequency (μslope1= -6.19, p < 0.001) significantly decreased during treatment, with no significant cross-lagged associations between homeless days and substance use frequency. However, results differed by race and ethnicity. For non-Hispanic White young adults, greater substance use at treatment entry was associated with steeper declines in homeless days between-persons (ϕstandardized = -0.14, p = 0.04). For African Americans, homeless days at treatment entry were associated with greater increases in substance use between-persons (ϕstandardized = 0.29, p = 0.04). No significant differences were found by sex or sexual/gender minority status. Conclusions: Despite overall declines in homelessness and substance use during treatment, these outcomes may unfold differently for non-Hispanic White and African American young adults. More support may be needed for African American young adults reporting homelessness at treatment entry.