The history of genetic analyses in the COGA Project spans linkage to genome‐wide approaches and reflects the evolution of gene identification efforts in psychiatric and behavioral genetics more broadly. Given the genetic tools available, the most powerful approach at the time of COGA's inception in 1989 was linkage analysis, a family‐based method. Thus, the initial COGA design was to assemble microsatellite marker data on families with three or more members affected by the then‐current diagnostic DSM3‐R 9 lifetime alcohol dependence (as well as Feighner definite criteria 10 ), and a smaller number of comparison families recruited from the same catchment areas that were neither screened to exclude, nor enriched for, alcohol dependence. 11 Initially, recruitment of affected individuals was from in‐patient treatment centers to ensure that they were severely affected. Individuals were interviewed, asked about their family structure, and upon consent, all further consenting members of families in which at least three first degree relatives (i.e., proband and two first‐degree relatives) met alcohol dependence lifetime criteria (DSM‐IIIR 9 and Feighner 10 ) were included. Out‐patient clinic recruitment was added shortly
