In the moderation model, an interaction term was created to measure the interaction between the polygenic score and intervention. This interaction term was a significant predictor of risk of first marijuana use (est.=−.400, S.E.=0.133, p=.003), suggesting that those individuals who received the classroom-centered intervention and who had a high polygenic score had the lowest risk of marijuana use from age 6 to age 18 (see Figure 1). In the presence of an interaction, we took the following steps to decompose the interaction to further facilitate its interpretation: hazard probabilities were plotted for the control and intervention groups at the mean level of the polygenic score (est.=−.198, p=.236, 95% CI[−.472, .077]), one standard deviation above the mean of the polygenic score (est.= −.598, p=.003, 95% CI[−.924, −.272]), and one standard deviation below the mean of the polygenic score (est.=.202, p=.374, 95% CI[−.172, .577]). As can be seen in Figure 1, hazard probabilities were lowest across waves for individuals in the intervention condition and one standard deviation below the mean for the polygenic score.
