Alcohol dependence (AD) and major depression (MD) are common psychiatric disorders that often co-occur. Alcohol researchers have frequently delineated different “types” of alcohol dependence, with a central distinction being the presence or absence of externalizing disorders, such as antisocial personality disorder, or internalizing disorders, including depression. For example, Cloninger et al. (1981) defined Type I alcohol dependence as that which is driven in part by drinking to self-medicate negative affect; Del Boca and Hesselbrock (1996) describe four types of dependence, including an “internalizing” type that exhibits high anxiety and/or depression, and consumes alcohol to alleviate anxiety or depression. Classes of alcohol dependent individuals who could be broadly described as suffering from mood and/or anxiety disorders have also been defined by others (Lesch et al., 1988; Windle and Scheidt, 2004).
