where β1 is the intercept, β2 is the slope for the linear time term (t), β3 is effect of sex on the intercept, and β4 is the effect of parental externalizing problems on life events, β5 is the effect of number of parental externalizing reporters on life events, b1 is the random intercept allowing for individual variation around the mean (β1), b2 is the random intercept allowing for individual variation around the slope (β2), and β1i and β2i denote the participant-specific intercepts and slopes.
