Affected Sib-Pair Substance and Alcohol Dependence (IASPSAD), and the Study of Addiction: Genetics and Environment (SAGE), with results expected imminently. Although GWAS provides several advantages, including the ability to more precisely localize associated variants, it also provides many challenges including the need for large samples to detect genes of small effect, many genetic markers, and multiple testing concerns.56 There are strengths and weaknesses to all gene-finding techniques, and converging evidence of association across techniques will be key to validating specific genetic variants involved in complex traits.
