What is a drug?
A drug is any substance, solid, liquid or gas, that brings about physical and/or psychological changes. The drugs of most concern in the community are those that affect the central nervous system. They act on the brain and can change the way a person thinks, feels or behaves. These drugs are known as "psychoactive drugs".
How are drugs classified?
Drugs are commonly classified according to their legal status or their effects on the central nervous system.
Legal and illegal drugs
Laws and regulations control the availability, quality and price of the "legal" drugs. For example, tobacco may not be sold to persons under the age of 18.
Illegal drugs
Because they are illegal, there are no price or quality controls on the illicit drugs such as heroin and ecstasy. This means that a user can never be sure that the drug they are taking is in fact what they think it is; for example, PMA (paramethoxyamphetamine), a toxic form of amphetamine, has been sold as ecstasy. The user also cannot be sure of a drug's strength or purity. Various batches of an illegally manufactured drug may have different mixtures of the drug and additives such as poisons, caffeine or even talcum powder.
Effects on the central nervous system
There are three main types of drug affecting the central nervous system.
Depressants
Depressants are drugs that slow down the functions of the central nervous system. Depressant drugs do not necessarily make a person feel depressed. They include:
Alcohol ("booze", "grog")
Cannabis ("pot", "dope", "mull")
Barbiturates, including Seconal, Tuinal and Amytal
Benzodiazepines (tranquilisers), "benzos", "tranx" such as Rohypnol, Valium, Serepax, Mogadon, Normison and Eupynos
GHB (Gamma-hydroxybutrate),