Bridging the Gap: Microtrials and Idiographic Designs for Translating Basic Science into Effective Prevention of Substance Use

Abstract

Prevention science is inherently pragmatic. While many mechanisms may contribute to risk for substance use and abuse, we are most concerned with those that are malleable through practical means. Basic research is most often focused on whether some mechanism increases risk or protection, with little attention to whether and how that mechanism can be changed. Applied research emphasizes pragmatic malleability, testing theories of how to change such mechanisms, as a basis for designing effective prevention programs. In this chapter we introduce two applied research designs that hold promise for developing and testing pragmatic malleability relevant for the prevention of substance use and abuse: microtrials and idiographic designs. Microtrials are brief experiments testing whether focused environmental manipulations can alter specific risk or protective mechanisms. We discuss how microtrials can be expanded to test whether interventions alter these mechanisms more strongly for some people than others and evaluate their strengths and limitations for substance abuse research. Idiographic designs use intensive repeated assessments to track continuity and change in key risk or protective mechanisms. They can be integrated with experimental designs to test intervention impact on risk and protective mechanisms as well as substance-use outcomes. We discuss several useful variants and review recent advances in statistical methods for handling the complex datasets they produce. We conclude with a discussion of how microtrials and idiographic methods can be used to enhance current substance-abuse prevention programs and support the development of more effective next-generation prevention trials.