The present study has notable strengths. Important alcohol transitions were examined, from first drink to the development of AUD. Alongside these transitions, behavioral indicators were examined both phenotypically and using PGS. Internalizing and externalizing phenotypes were measured by multiple discrete symptoms, allowing for fine-grained analysis that shows that social anxiety, suicidal ideation, conduct disorder, and hyperactive ADHD symptoms may be uniquely related to alcohol milestones. By examining bidirectional associations, a truly developmental model was adopted that begins to capture the dynamic process by which AUD and comorbid symptoms develop over time, with implications for intervention and etiologic understanding.
