Self-administration 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 in a 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 pro- Received March 2, 1999; revised August 25, 1999; accepted December 6, 1999. 582 A.J. Roberts et al. N EUROPSYCHOPHARMACOLOGY 2000 -VOL . 22 , NO . 6 tracted symptoms tended to be subacute, were often affective in nature, and appeared to precede relapses into uncontrolled alcohol drinking. For example, depression and anxiety associated with withdrawal were found to provoke drinking in 83 of 100 male alcoholics who experienced these symptoms (Hershon 1977). These patients reported that they drank alcoholic beverages when they experienced anxiety and depressed mood. In another study, both male and female alcoholics reported negative emotions as the most common trigger of relapse (Annis et al. 1998). The clinical literature suggests that alterations in affective state persist for quite some time following alcohol withdrawal and may actually be partly responsible for some relapse episodes in alcoholics.Potential rodent models of excessive ethanol drinking include the alcohol deprivation effect in nondependent animals, ethanol self-administration in dependent withdrawing animals, and ethanol self-administration in animals with a history of dependence following periods of abstinence. The alcohol deprivation effect is a transient increase in ethanol self-administration in animals following periods of abstinence from ethanol for several days to several weeks (Sinclair and Senter 1967;Spanagel et al. 1996;Heyser et al. 1997;Hölter et al. 1998). This increase in e...