Weighted Family History Density of Substance Use: Influence on Participant Substance Use Onset, Duration, and...

This study investigates how weighted family history density (WFHD) influences the intergenerational transmission of substance use disorders (SUDs), focusing on onset, escalation, and duration of substance use. Substance preference concordance and sex-specific links between affected family members and participants were also assessed.

A cross-sectional analysis of the National Epidemiological Survey on Alcohol and Related Conditions III (NESARC-III) included 36,309 adults. WFHD was defined as drug or alcohol problems among first- and second-degree relatives. Linear regression models assessed the relationships between WFHD, age at onset, and duration of substance use, adjusting for sociodemographic factors. The escalation period to peak alcohol use was plotted by WFHD level, and correlation analyses examined the role of affected family members in shaping participant substance preferences and sex-stratified SUD diagnoses.

Each unit increase in WFHD was linked to a minimum 0.53-year earlier onset [β = -0.53, SE = 0.02] and 0.48-year longer duration (β = 0.48, SE = 0.03) of substance use. WFHD increased the adjusted odds of onset before age 18 by 27% and duration exceeding half of one's age by 19%. Adjusted odds for durations exceeding 5 and 10 years rose by 26% and 21%, respectively. Higher WFHD was linked to faster escalation to peak use. Substance preferences showed significant concordance within families. Males were most strongly associated with paternal use, while females were more closely linked to maternal use.

Higher WFHD is strongly associated with earlier initiation, faster escalation to peak use, prolonged duration of substance use, and patterns of substance preference concordance, highlighting the importance of including family history assessments in substance use prevention and intervention strategies. Future research should use longitudinal studies to establish causal relationships and explore interactions between WFHD and other risk factors, such as environmental stressors, epigenetic changes, or genetic markers.