Polygenic Risk for Substance Use Disorders as Predictors of Substance Use Initiation Among African American Youth

Area of Science:

• Genetics
• Psychiatry
• Public Health

Background:

• Early substance use initiation is linked to adverse health outcomes.
• Limited understanding exists regarding genetic risk and environmental moderators of substance initiation, especially in African American youth.
• This study investigates genetic predisposition and environmental factors influencing substance initiation age.

Purpose of the Study:

• To examine the association between genetic risk for alcohol use disorder (AUD), cannabis use disorder (CUD), and nicotine dependence with age at initiation of these substances.
• To investigate whether community disadvantage and parental monitoring moderate these genetic associations in African American youth.

Main Methods:

• Recruited 1,017 African American youth for a universal prevention trial.
• Collected data on age at alcohol, tobacco, and cannabis initiation, genetic risk scores (PRS), parental monitoring, and community disadvantage.
• Utilized Cox Proportional Hazard Models to test hypotheses.

Main Results:

• Higher AUD polygenic risk scores (PRSs) were associated with later alcohol initiation (HR=0.78).
• CUD and nicotine dependence PRSs were not significantly associated with initiation age.
• An interaction was found between CUD PRS and parental monitoring, influencing cannabis initiation age.

Conclusions:

• Genetic risk scores for substance use disorders generally do not predict initiation age in this cohort.
• Parental monitoring may interact with CUD genetic risk to affect cannabis initiation timing.
• Further research is required to validate these findings.