12 years old and in 6th grade, younger than those in the comparison families, and substance use initiation was not yet a common behavior. The lower prevalence of substance involvement among case family children compared with their comparison family counterparts is probably due to being several years younger, on average. A striking but unsurprising observation is that only 48% of the children in case families were living with their biological father, compared with 96% of children in comparison families. In children from case families, comorbidity with attention deficit‐hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), anxiety, and depression, reported by either the child or parent, was elevated over that observed in children from comparison families.
