Proportions of first use at each age can be seen in Table 1. The proportion of individuals initiating began at only 1% of the population at the first time point. Subsequently, there was an increase in first use rates across the time period, peaking at age 13 and age 14, with around 20% of the remaining sample initiating at each age respectively. At the last time point, 15% of the remaining sample reported their first use. Mean scores for fall teacher rated aggression and the polygenic score can also be seen in Table 1.
