We initially tested for an association between the four genes and alcohol dependence as defined by DSM-IV criteria (American Psychiatric Association, 1994). Secondary hypotheses based upon both the human and animal literature included alcohol withdrawal symptoms, such as seizures, and cocaine dependence. The number of affected subjects analyzed for each phenotype is shown in Table 1. Using items from the SSAGA, two measures of alcohol withdrawal were analyzed. The first was whether an individual ever experienced any of nine problems (shakes, sleeplessness, anxiety, sweating, fast heart beat, nausea/vomiting, physically weak, headaches, or seeing/hearing things that weren’t there) after having stopped, cut down, or gone without drinking. Subjects were classified as affected if they met three criteria: 1) responded affirmatively to having at least one of the problems; and 2) took any medication/drug to avoid any of these problems (or to make them go away); and 3) were classified as DSM-IV alcohol dependent. The medication requirement was included in order to more closely approximate the “severe” withdrawal of Koehnke et al. (Koehnke et al., 2002). Subjects were coded as unaffected if
