This study investigated the incidence and patterns of substance use in
a schoolage population, as well as predictive risk factors that may p
lay an important role in understanding its initiation. Low socioeconom
ic status Mexican American fourth-, fifth-, and sixth-grade students w
ere surveyed for two consecutive years in order to obtain information
on their substance use and its relationship to specific demographic, e
nvironmental, and psychological risk factors. Results capture patterns
of substance use among this population over the two years, as well as
the relationship between reported risk factors in year one and the us
e of minor and major substances in year two.