"Exposure to early life stress, even to more severe forms such as physical and sexual abuse and emotional neglect, is common in the general population. The degree of risk for adult psychopathology tends to be correlated with the severity of childhood maltreatment and the number of childhood SLE [stressful life events]. An important causal pathway that links early life stress to the onset of psychiatric disorders is the altered homeostasis in the HPA [hypothalamicpituitary-adrenal] axis and the altered stress response circuitry that underlies many disorders including anxiety, depression, PTSD, and addiction. There appears to be a direct pathway from chronic stress exposure in prepubertal children via adolescent problem drinking to alcohol and drug dependence in early adulthood that is independent of family history. Of course, this can only occur in individuals exposed to the availability of alcohol or drugs. Early life stress may increase vulnerability to addiction through permanent effects on the expression of genes within the mesolimbic dopamine reward pathway. Early onset of problem drinking in stress-exposed children may exacerbate the deleterious effects on the developing brain. Since a large proportion of stress-exposed children do not go on to develop addiction, clearly resilience factors, including gene–environment interactions, are important. This review of the literature indicates that prevention should focus on early intervention in problem families to forestall maltreatment. Adolescence is a critically vulnerable time for the development of risky drinking habits, and this is an area where prevention, through the development of positive family, peer, and neighborhood-mediating factors, is vital. A holistic approach to the treatment of alcohol and drug dependence is essential since treatment is unlikely to be effective unless underlying impediments such as early life stress are recognized and addressed."

Source

Enoch, Mary-Anne, "The role of early life stress as a predictor for alcohol and drug dependence," Psychopharmacology (Heidelberg, Germany: July 2010) Vol. 214, No. 1.