When having a continuous free choice in their home cages between water and alcohol- or drug-containing drinking solutions,
rats first develop a controlled consumption of the psychotropic compound and, after several months, lose their control over
drug taking. After a long period of abstinence, they reveal an excessive, compulsive drug intake. Adulteration of the drug-containing
solutions reduces the doses taken by controlled consumers, but not those of the excessive drinkers, they can therefore be
regarded as addicted. These animals show a pre-intake motor restlessness that may be related to craving. In two studies with
putative anti-craving agents (the dopamine D
2 receptor agonist lisuride and the D
2 receptor antagonist flupentixol) we treated alcohol-addicted and non-addicted rats and observed the effects on alcohol taking,
alcohol seeking and brain neurotransmission. These two investigations paralleled clinical studies, in both cases the results
could be predicted correctly (“pro-craving” effect of both pharmaceutics). Differences between “symptomatic” and possible
“causal” therapies are discussed, approaches towards a causal therapy according to an "imprinting"-model of an addition are
suggested.
Keywords: Rat, drug self-administration, drug dependence, imprinting, alcohol, flupentixol, lisuride.
Received August 18, 1999; accepted November 3, 1999