In the EA sample, parental separation and parental relationship discord were associated with baseline levels of HED (intercept), but not with its escalation (linear slope) or reduction (quadratic term). This is consistent with prior evidence linking parental separation and discord to earlier alcohol milestones, such as early initiation1,41 and higher misuse in adolescence.10 Because most young adults no longer live with one or both parents, the ongoing influence of parental separation and relationship discord on daily functioning may be diminished, which could explain why these factors were associated with baseline levels of HED in adolescence but not with its rate of escalation over time across young adulthood. This underscores the impact of familial stressors on the early stages of alcohol misuse. Our results suggest that the previously noted cross-sectional variation in alcohol misuse associated with parental separation42 are driven largely by initial HED levels in adolescence, with these differences persisting over time.
