Abstract

We used short message service surveying (SMS) with 150 homeless youths to examine the time ordering of feeling depressed with drinking alcohol, using marijuana, and using substances with friends. Multilevel binary logistic regression results revealed that youths who were depressed earlier in the day were more likely to drink alcohol later that day. Among depressed youths, heterosexual youths were less likely to drink alcohol than lesbian, gay, and bisexual (LGB) youths. Depressed youths had increased odds of using marijuana by a factor of 1.6, while heterosexual youths, compared to LGB youths, were 80% less likely to use marijuana. Females were 82% less likely and heterosexual youths 75% less likely to use substances with friends compared to males and LGB youths, respectively. These findings improve upon prior retrospective studies by using SMS to understand time ordering between feeling depressed and substance use in the same day.