Parental separation, like parental AUDs, was more strongly associated with early than later age at initiation. Subjects who did not grow up with both biological parents, compared to those who did, were at increased risk for first use of alcohol before age 13 (HR=2.16) and for initiating cigarette and cannabis use before age 16 (HRs=1.89 and 2.03, respectively), as well as increased risk for sexual debut before age 16 (HR=2.34).
