Excessive drinking of ethanol in animals can be produced by a number of factors including altering palatability,
genetics, and history of consumption. There is evidence that certain symptoms of withdrawal can persist for a
number of weeks or even months following chronic ethanol exposure in humans (Kissin 1979; Begleiter and Porjesz 1979; Alling et al. 1982; Roelofs 1985; Grant et al. 1987) as well as in animals (Begleiter and Porjesz 1979). In human alcoholics, one of the factors leading to excessive drinking is the use of alcohol to relieve or avoid withdrawal symptoms (U.S. Department of Health and Human Services 1990). Fatigue and tension persisted for approximately five weeks following withdrawal in a group of 68 chronic alcoholics (Alling et al. 1982), and periods of
hyperventilatory symptomology and anxiety (as determined by the Spielberger State-Trait Anxiety Inventory, a self-report inventory), which correlated with intensity of alcohol craving, were reported for up to nine months following withdrawal ina group of 37 chronic alcoholics (Roelofs 1985). In a larger cohort of 312 abstinent alcoholics, 20–25% of them showed signs of anxiety and depression, as determined from the Symptom Check-List 90 (self-report inventory with coverage of areas of symptomology and psychopathology) six months to two years following withdrawal (De Soto et al. 1985). In a follow-up study, it was shown that distress-related symptoms correlated with relapse in alcoholics who were abstinent for less than two years (De Soto et al. 1989). The more protracted symptoms tended to be subacute, were often affective in nature, and appeared to precede relapses into uncontrolled alcohol drinking.