NTR subjects who participated in the GAIN-NTR study were excluded because those subjects were included in the original TAG meta-analyses. Family members of subjects in the GAIN-NTR study were also excluded (except non-biological members like spouses of twins). This resulted in a sample of 1583 subjects with genotype data, and 72% of the sample was female. The year of birth ranged between 1915–1994 (median 1958). Subject were from European decent.
