This was based on an advice of a WHO Expert Committee3, that suggested the generally accepted notion of 'drug dependence'4 to be augmented with an addition relating it to a certain group of drugs in order to differentiate between the dependence on one group of drugs and that on another group of drugs, the laudable intention being to indicate that different types of drugs produce different types of dependence with different clinical syndromes and consequences5. But the creation of drug dependence-LSD type was not rational at all as already everybody knew at that time that LSD does not create dependency of any type. But it had as a consequence that the hallucinogens are defined as addiction producing drugs, to be subsequently prohibited by the Vienna Treaty. Although the position taken by the signatories of these international conventions and treaties is clearly moral as shown by the improper handling of the idea of dependency, it does not follow logically that dependency creating properties of a drug might not serve as a criterion to differentiate. The question is however whether or not we can measure the addictive properties of drugs.
Some pharmacologists consider addictive property as a property of the substance.
They use the paradigm of selfinjecting behavior of experimental animals as yardstick. Although interesting from the point of view of a neuroscientist, to unravel the intricacies of the brains internal reward system, I feel these experiments to be less interesting when applied to the questions regarding addiction. The difference between cocaine and heroin may illustrate this. The results of animal experiments however tend to show that cocaine is the stronger rewarding of the two. At least other factors, non pharmacological in nature, have an overriding influence on the outcome.