The causal impact of older siblings’ academic achievement on younger siblings’ risk for drug use disorder: instrumental variable and propensity score analyses

Key Points

• To explore the causal relationship between older siblings' academic achievement and younger siblings' risk for drug use disorder.
• Utilized instrumental variable analysis to assess causal impacts.
• Applied propensity score methods to control for confounding variables.
• Focused on sibling pairs for a comparative analysis.
• Identified a significant causal link between low academic achievement in older siblings and increased drug use disorder risk in younger siblings.
• Observed stronger effects in closely aged sibling pairs, particularly among male-male pairs.
• Suggested that improving older siblings' academic achievement could indirectly benefit younger siblings by reducing drug use risk.