... there is scarcely any agent which can be taken into the body to which some individuals will not get a reaction satisfactory or pleasurable to them, persuading them to continue its use even to the point of abuse ... Eddy (1965) Dependence is one of the major problems of our modern society both in industrialized and developing nations. There is, however, nothing new in man's dependence on drugs. For many centuries past, there can be few people throughout the world who do not 'overuse', 'misuse' or 'abuse' some drugs. For many the drugs that are 'overused' are caffeine (from tea or coffee), nicotine (from tobacco) or alcohol (from beer, wine or spirits), all socially accepted normal ingredients of everyday life in most communities. For a smaller group 'misuse' concerns commonly prescribed medical substances, such as barbiturates, amphetamines. For an even smaller group there is the less socially acceptable 'abuse' of specific drugs such as morphine and related analgesics, cannabis, or hallucinogens.