Exposure to childhood adversity and adult alcohol, nicotine, and illicit drug use in Germany: a cross-sectional analysis of the German National Cohort (NAKO)
Rationale: Exposure to adversity in childhood and adolescence (i.e., "early-life stress"; ELS) is a well-established risk factor for substance use. Objectives: The aim of this study was to investigate associations between ELS exposure and substance use across subtypes of ELS, different substance classes, and behavioral profiles of substance use. Methods: In this cross-sectional study, we examined associations between ELS exposure and substance use in a population-based sample of 172,173 adults aged 19-74 years from the German National Cohort (NAKO). ELS exposure was assessed using the Childhood Trauma Screener. Substance use included nicotine, alcohol, and illicit drug use. Associations were examined using regression models evaluating overall ELS exposure, cumulative trauma load, and ELS subtypes. Latent class analysis (LCA) was conducted to identify substance use profiles. Results: ELS exposure was associated with higher odds of smoking, greater smoking severity, heavier alcohol consumption among drinkers, and higher odds of lifetime illicit drug use. Overall, the strongest associations were observed for opioid and stimulant use. Dose-response analyses revealed higher risk with increasing numbers of ELS subtypes. Abuse-related subtypes, particularly exposure to physical and sexual abuse, consistently showed strongest independent associations across substances, whereas neglect exhibited weaker, more variable associations. LCA identified four substance use profiles, with ELS exposure predicting membership in more severe polysubstance classes. Conclusions: ELS emerged as a robust risk factor for adult substance use, underscoring the need for trauma-informed approaches in clinical practice, public health, and policy to mitigate the long-term consequences of early adversity.