the Denver area. Probands were selected from individuals who had consecutive admissions to the treatment facilities between February of 1993 and June of 2001. Controls were recruited from the community and matched to the clinical probands based on age, gender, ethnicity, and zip code. All individuals living in the same household as the proband were asked to participate in the study, which created family-based data. For this study data from both wave 1, data collection for which began in 1997 and ended in 2002, and wave 2, data collection for which began in 2002 and ended in 2008, were used. When assessed, buccal cell DNA was collected from subjects who gave voluntary consent. All recruitment, assessment, and DNA collection procedures were approved by the University of Colorado's IRB.
