Geographical proximity and the transmission of drug abuse among siblings : Evaluating a contagion model in a Swedish National Sample
AimsCan drug abuse (DA) be transmitted psychologically between adult siblings consistent with a social contagion model?MethodsWe followed Swedish sibling pairs born in 1932-1990 until one of them, sibling1 (S1), had a first DA registration. We then examined, using Cox regression, the hazard rate for a first registration for DA in sibling2 (S2) within 3 years of a first DA registration in S1 as a f