The author did beforehand a brief historical survey of drug usage, going throught the concepts of what might be called classic drug addiction, until the present stage of the phenomena of what is known as contemporary drug addiction was reached. Accepting the clinical reality of psychiatric accidents, as presented by the classic psychiatric nosological classification as a fact, the author points out the possibility for establishing a relation between the misuse of toxicomanogenic substances and the frequently pre-morbid personality of the user.