Subjects in the FSCD were specifically recruited for cocaine use from chemical dependency treatment units in the greater St Louis metropolitan area. The Missouri Family Registry identified community-based control subjects and matched them by age, race, gender and residential zip code. Controls were biologically unrelated individuals from the same communities who consumed alcohol, but had no lifetime history of dependence on any substance23. FSCD contributed 218 individuals with DSM-5 cocaine use disorder and 76 individuals without DSM-5 cocaine use disorder (51 non-exposed controls and 25 exposed but without DSM-5 cocaine use disorder).
