(alternatively, , , or ) is a comprehensive catchphrase for the medical theory that the use of a psychoactive a psychoactive drug can be coupled to an increased probability of the use of further drugs. Possible causes are biological alterations in the brain due to the earlier drug and similar attitudes of users across different drugs ( common liability ). ). Scientific investigation of the possible causes is considered important for health policy concerning education and law making.
A , or , is a drug that lowers neurotransmission levels, which is to depress or reduce arousal or stimulation, in various areas of the brain.[1] Depressants are also occasionally referred to as "downers" as they lower the level of arousal when taken. Stimulants or "uppers" increase mental and/or physical function, hence the opposite drug class of depressants is stimulants, not antidepressants. Depressants are widely used throughout the world as prescription medicines and as illicit substances.
are that speed up the activity of the central nervous system. are useful in treating many medical conditions, including ADHD, narcolepsy, asthma, obesity, and depression. There are several types of , including caffeine, nicotine, cocaine, amphetamines, and methamphetamines.
The 1961 Convention exercises control over more than 116 . They include mainly plant-based products such as opium and its derivatives morphine, codeine and heroin, but also synthetic such as methadone and pethidine, as well as cannabis, coca and cocaine.
Hallucinogenic drugs, also known as ‘psychedelics’, are drugs that change the way a person perceives the world. Hallucinogens affect all the senses, altering a person's thinking, sense of time and emotions.
Some examples of hallucinogens include:
LSD (lysergic acid diethylamide); PCP (phencyclidine); magic mushrooms (psilocybin); ketamine; mescaline (peyote cactus); morning glory seeds; datura.
Inhalants are volatile substances that produce chemical vapors that can be inhaled to induce a psychoactive, or mind-altering, effect. Although other abused substances can be inhaled, the term "inhalants" is used to describe a variety of substances whose main common characteristic is that they are rarely, if ever, taken by any route other than inhalation.
