The authors explored the relationship between the history of parental probl
ematic alcohol and drug rise and their adult children's alcohol and drug us
e disorders. Subjects were 347 admissions to an outpatient substance abuse
program. There was a positive relationship between the number of parents af
fected by alcohol and/or drug problems and the percentage of probands with
co-existing alcohol and drug use disorders for probands with alcohol use di
sorders but not for those with only drug abuse. Probands with two affected
parents had significantly higher alcohol abuse scores and drug, family, and
psychiatric composite test scores than those with a negative family histor
y. This preliminary study indicates that the severity of a proband's substa
nce use disorder may be influenced by parental substance use history.