Objectives: The present investigation examined the role of sex, family history of alcohol and drug use disorders, temperament, childhood behavior problems, and adult psychopathology on adult alcohol use disorder (AUD) severity. Methods: Structural equation modeling was used to examine multiple etiological pathways to adult AUD severity. Participants included 335 treatment-seeking male and female individuals with current or lifetime DSM-III-R alcohol dependence (96%) or abuse (4%) enrolled in 1 of 5 treatment outcome studies. Extensive assessment at treatment entry used a mixture of retrospective and current self-report. Results: Results identified 2 significant paths associated with a latent factor of adult AUD severity at entry to treatment. In path 1, male sex and family history of drug use disorder predicted greater childhood behavior problems, which predicted antisocial personality disorder, borderline personality disorder, and anxiety disorders, with anxiety disorders leading directly to AUD severity. In path 2, family history of AUD predicted difficult temperament in childhood, which predicted borderline personality disorder, major depressive disorder, and anxiety disorders; both major depressive disorder and ADs in turn predicted AUD severity at treatment entry. Conclusions: The present findings build on the literature on heterogeneity in developmental risk processes leading to the expression of adult AUD symptomology among patients presenting for AUD treatment.