Early initiation of substance use significantly increases one's risk of developing substance use dependence and mental disorders later in life. To interrupt this trajectory, effective prevention during the adolescent period is critical. Parents play a key role in preventing substance use and related harms among adolescents and parenting interventions have been identified as critical components of effective prevention programs. Despite this, there is currently no substance use prevention program targeting both students and parents that adopts online delivery to overcome barriers to implementation and sustainability. The Climate Schools Plus (CSP) program was developed to meet this need. CSP is an online substance use prevention program for students and parents, based on the effective Climate Schools prevention program for students.

This paper describes the development of the parent component of CSP including a literature review and results of a large scoping survey of parents of Australian high school students (n = 242). This paper also includes results of beta-testing of the developed program with relevant experts (n = 10), and parents of Australian high school students (n = 15). The CSP parent component consists of 1) a webinar which introduces shared rule ranking, 2) online modules and 3) summaries of student lessons. The parent program targets evidence-based modifiable factors associated with a delay in the onset of adolescent substance use and/or lower levels of adolescent substance use in the future; namely, rule-setting, monitoring, and modelling. To date, this is the first combined parent-student substance use prevention program to adopt an online delivery method.