Aims To identify childhood risk factors that predict (a) age of first drink and (b) time from first use to alcohol dependence (AD) onset, using survival analysis.
Participants The sample consisted of 1269 offspring (mean age = 20.1 years) of male twins from the Vietnam Era Twin Registry; 46.2% were offspring of alcohol-dependent fathers.
Measurements DSM-IV psychiatric diagnoses and substance use behaviors were assessed by structured telephone interview.
Findings First drink occurred on average at 15.7 years; AD onset at 19.1 years. A Cox proportional hazard regression analysis revealed conduct disorder (CD) as the most potent predictor of early alcohol initiation (HR 2.48; CI 1.85–3.32). Attention deficit hyperactivity disorder (ADHD), maternal AD, paternal AD, male gender and parental divorce were also associated with early first use (HR 1.20–1.52; CI 1.04–1.39–1.18–1.96). A Cox proportional hazard regression analysis modeling first drink to AD identified nicotine dependence (HR 3.91; CI 2.48–6.17) and generalized anxiety disorder (GAD) (HR 3.45; CI 2.08–5.72) as robust predictors of progression to AD. CD (HR 1.75; CI 1.10–2.77) and cannabis abuse (HR 1.88; CI 1.22–2.90) were also associated with rapid transition to AD.
Conclusions Results highlight the role of psychiatric and substance use disorders in progression from first drink to AD, underscore the continuity of risk associated with CD and indicate that (with the exception of CD) different factors play a role in transition to AD than in initiation of alcohol use. Distinctions between stages are interpreted in a developmental framework.