Subjects were classified as genetically AA or EA on the basis of the AIMs panel, using the program STRUCTURE v 2.3.2.1 (51), as described previously (52). Among the subjects included in the current study, 2 subjects reporting to be of AA descent clustered in the EA group, and 2 subjects reporting to be EA clustered in the AA group. Adjusting for the degree of admixture did not significantly change our results on the influence of COMT Val158Met variation on the study outcomes.
