Introduction:
Much less was known about early adolescents’ purchasing substance for parents and others and its association with their substance use.

Objectives:
This study aimed at examining the protective and risk factors for adolescents’ substance use and identifying if early adolescents’ purchase of substance for others mediated the effects of knowledge, attitudes toward substance use, family communication patterns and parent-early adolescent use of alcohol, betel nuts and cigarettes.

Methods:
The investigators performed a stratified and random sampling by interviewing 519 dyads of parents and early adolescents by asking a self-reported questionnaire from an eastern county in Taiwan. The total of 379 dyads was analyzed after excluding missing values and invalid answers.

Results:
The evidences support that early adolescents purchasing betel nuts for others mediated both effects of pro-substance attitude (p< 0.001) and parents ever used betel nuts (p< 0.01) on the use of betel nuts. Similarly, early adolescents’ ever bought alcohol for others significantly mediated the attitudes toward pro-substance on their drinking alcohol (p< 0.01). Specially, the findings illustrate that early adolescents have purchased cigarettes for others significantly mediated the effect of parents’ betel nut use (p< 0.01) on the early adolescents’ cigarette use.

Conclusion(s):
We concluded that early adolescents purchased substance for others rather than their parental substance use and family communication patterns impacted on their attitudes and substance use in high risk communities. The findings could be considered for developing substance preventive campaigns by targeting at early adolescents and their parents.