ABSTRACT
The use of drugs that produce powerful effects on mood, affect, and thinking and alter levels and states of consciousness has been a part of our civilization since recorded history. This refers to both illicit substances (e.g., opium, cocaine, cannabis, synthetic psychoactive substances) as well as to licit and commonly available drugs (e.g., alcohol, tobacco, caffeine-containing beverages). Although the latter group of substances raises fewer emotionally heated societal concerns than the former, use and misuse of these substances are also discussed in this chapter.
