The Collaborative Genetic Study of Nicotine Dependence (COGEND) was initiated in 2001 as a three-part program project grant funded through the National Cancer Institute12. Nicotine dependent and non-dependent smoking subjects were recruited from communities in Detroit and St. Louis, using a Health Maintenance Organization in Detroit and the Missouri Family Registry in St. Louis maintained at Washington University for research purposes. Nicotine dependent subjects were current smokers with a Fagerström Test for Nicotine Dependence (FTND)13 score of 4 or more. Non-nicotine dependent subjects were individuals who smoked at least 100 cigarettes lifetime, who never had any symptoms of dependence (lifetime FTND=0). For this study 2666 COGEND subjects were used, including 612 DSM-IV alcohol dependent cases and 2054 non-alcohol dependent controls. This sample includes 1610 subjects who were previously examined in Sherva et al., 200914.
