. Author manuscript; available in PMC: 2018 Jun 1.

Published in final edited form as: Mol Psychiatry. 2017 Jan 10;22(12):1767–1775. doi: 10.1038/mp.2016.239

Table 1.

Descriptive characteristics of analytical COGA samples

	AA fGWAS genotyped sample	AA fGWAS fast beta EEG subsample	AA fGWAS fast beta EEG subsample with DSM-IV data	AA prospective study subsample (at baseline)
Genotyped (N)	3414	2382	2242	892
Families (N)	598	482	480	212
Female (%)	52.7%	50.3%	53.4%	52.3%
Self-identified as ‘Black/African-American’ (%)	99.5%	97.9%	97.4%	92.7%
Age (mean, s.d.), years	32.4 (11.2)	29.4 (12.3)	29.9 (11.8)	16.1 (3.3)
Ever drinkers	92.2%	92.3%	89.5%	33.8%
DSM-IV AD diagnosis (%)	27.6%	23.6%	24.5%	1.8%

Abbreviations: AA, African-American ancestry; AD, alcohol dependence; COGA, Collaborative Study on the Genetics of Alcoholism; DSM-IV, Diagnostic and Statistical Manual of Mental Disorders; EEG, electroencephalography; fGWAS, function genome-wide association study.