The causal impact of older siblings’ academic achievement on younger siblings’ risk for drug use disorder : instrumental variable and propensity score analyses
Background Drug use disorder (DUD) clusters in families due partly to shared environment, including sibling influences. Low academic achievement (AA) in adolescence increases DUD risk. This study examined whether low AA in an older sibling causally increases DUD risk in younger siblings. Methods We studied all Swedish full sibling pairs (n = 309,666) born 1972–1985 and ≤ 5 years apart. Older sibli
