Defining the phenotype of young adults with family histories of alcohol and other substance use disorders: Studies from the family health patterns project.

Individuals with a family history of alcohol and other drug use disorders (FH+) are at increased risk for developing substance use disorders themselves relative to those with no such histories (FH-). Here we sought to identify key characteristics associated with FH+ status and alcohol and other drug use disorder status in a large cohort of FH+ and FH- young adults. We conducted principal component analyses on demographic, temperament, and cognitive measures differentiating 506 FH+ and 528 FH- young adults. Three principal components were identified, and these component scores were then used to predict the odds of being FH+ and the odds of having an alcohol or other drug use disorder. Component 1 consisted of measures indexing internalizing traits, with higher component scores indicating greater depressive, anxious, and emotional instability tendencies. Component 2 consisted of measures of externalizing traits as well as exposure to early life adversity (ELA), with higher scores indicating less impulse control, more antisocial behavior, and greater ELA exposure. Component 3 consisted of estimated intelligence, delay discounting, and demographic characteristics, with higher scores indicating lower estimated intelligence, greater discounting of delayed rewards, less education, and lower childhood socioeconomic status. For each 1-point increase in the Component 1, 2, and 3 scores, the odds of being classified FH+ increased by 2%, 8%, and 4%, respectively. Similar findings were observed when individuals with alcohol or other drug use disorders were removed from the analyses. Finally, greater Component 2 scores were also associated with increased odds of having an alcohol or other drug use disorder. Collectively, these findings provide a more comprehensive understanding of the FH+ phenotype in young adults and help form a basis for further studies on biological mechanisms underlying risk for substance use disorders. The present findings also provide further support for a prominent role of ELA in promoting risk for problem alcohol and other drug use.