Genetics can account for up to 30–60% of LR (Schuckit, 1999; Heath et al., 1999; Viken et al., 2003, Schuckit et al., 2005a). LR may also occur more in those with a family history of alcohol dependence (FHA) and is lower in males than females (Schuckit and Smith, 2004; Eng et al., 2005; Schuckit et al., 2005a; Schuckit et al., 2006).
