Developmental momentum toward substance dependence: Natural histories and pliability of risk factors in youth experiencing chronic stress

Background: Mitigation of substance use (SU) disorder (SUD) risk factors is a common goal of prevention. Research has clarified much about risk factors including their prediction of SU/SUD, associations with other etiological variables and mediation of SU outcomes. Greater understanding of the emergence of risk factors themselves may improve prevention. For example, in lieu of experimental data, the level of resistance to change of a risk factor (its pliability) could inform "dosage" of intervention needed to reduce the risk. Methods: Two attributes of 22 previously-documented predictors of SU/SUD were quantified: natural history (average age-related trend) and pliability (quantified using correlations between intercepts and growth parameters of hierarchical linear modeling trajectories). The longitudinal sample of 1147 8- through 16-year-olds were recruited from a northeastern summer camp for youth experiencing chronic stress due to one or more stressors (X̄=2.2 stressors, SD = 1.41) which typically last at least one year. Half were male, 69.3% were European-American, 8.5% were African-American, and the remaining were small proportions each of other or mixed races/ethnicities. Results: Average trajectories of 21 predictors correspond to increasing SUD risk with age. Predictor pliability varied greatly, ranging from extremely high for School Commitment to extremely low for Peer Pressure Susceptibility. Conclusions: Results suggest different intervention strategies may be needed to manage risk factors over the long-term. To illustrate, maintaining a high school commitment appears to require boosters whereas reducing peer pressure susceptibility appears to require high initial "dosage" with less need for boosters.