The goal of the Collaborative Study on the Genetics of Alcohol (COGA) is the elucidation of genetic mechanisms which influence susceptibility to alcohol abuse and dependence. Six different sites (University of Connecticut - Department of Psychiatry; SUNY - Down State - Department of Psychiatry; Indiana University - Department of Medicine; Iowa University - Department of Psychiatry; Washington University (St. Louis) - Department of Psychiatry; and University of California (San Diego) - Department of Psychiatry) are involved in this large scale family study of persons being treated for alcoholism. Multi-dimensional phenotypes, suitable for genetic linkage and for candidate gene studies, will be derived from the comprehensive assessment battery that involves a detailed examination of medical and psychiatric conditions, biochemical factors, and cognitive/electrophysiological factors. Control families are available in the sample. Lymphoblastoid cell lines are being developed so that DNA will be available and insure the utility of the sample for many years. An ongoing quality assurance program and follow-up assessments are included in this phase of the study so that phenotypic measures are as reliable as possible. To date, more than 8,500 subjects, representing 1,200 families nation-wide, have been recruited into the study. At the U Conn site, more than 1,200 subjects have participated in the COGA project. In the coming year, it is anticipated that 450 subjects will be assessed; approximately 50% of these will participate in the biological assessment including blood chemistries and electrophysiological assessment.