• Drug: Name given to all natural or synthetic substances, such as cocaine, morphine, heroin, derivatives of Indian hemp, amphetamines, some of which can be used for therapeutical purposes, but whose illegal and repeated usage, in order to escape reality, causes addiction and leads to drug dependence .
• Narcotic: Term derived from the Greek word narkôtikos , “that causes stupor”. Substance whose properties produce numbness, profound sleep. Narcotic remedy. Subst . Narcotic.
• Psychotropic: (drug or substance) acting on the mind and altering behaviour. Psychotropic drugs group various agents, including agents altering behaviour through direct or indirect action on the central nervous system, or through peripheral action (Translated from Méd. Biol . t. 3 1972).
• Stupefacient: (toxic substance) acting on the nervous system, inducing an analgesic, narcotic or euphoria effect, and causing habituation and dependence if used repeatedly.
• Toxicomania (drug addiction) : Insane desire for natural or medicinal toxic substances (stupefacients, anti-depressants, stimulants). Its use induces a craving and dependence of the organism.
• Physical dependence: Physical tolerance of the organism through the use of psychotropic drugs. Interruption of use causes the appearance of physical symptoms (pain, digestive signs...), and psychological symptoms (nervousness, violent behaviour, aggression, depression syndromes…) whose importance and duration give an indication of the extent of the physical dependence . It is an ill being and a craving appearing upon discontinuance of regular drug consumption.
• Psychological dependence: It can intervene rapidly even when the level of use is low. Its intensity varies from one individual to another and depends on the types of substances used. It is reflected by a state of psychological depression felt when the effects desired have disappeared, and the drug addict develops a compulsive need for consuming psychotropic substances to achieve the same effects.
• Tolerance: Tolerance is the need for the user to increase his/her dosage in order to attain comparable effects. The mechanisms of tolerance can be both physiological and psychological.
• Withdrawal syndrome: Physical and psychological symptoms that follow discontinuance of drug usage. The intensity of these symptoms depends on the patients and the type of drug used. Abrupt discontinuance of the use of a drug can be lethal and should be supervised medically if an individual is withdrawing from drug addiction.