Any psychoactive substance, i.e. a substance that, if taken in sufficient dose, can alter mental and physiological processes. Examples of drugs include alcohol, tobacco, illegal substances (i.e. those whose production, sale, or use is forbidden or limited under international and national drug control laws and treaties), volatile substances (gases, fumes from glues, aerosols and similar products), over-the-counter and prescription medicines and new psychoactive substances (e.g. “legal highs”). Drugs are also known as substances or compounds; illegal drugs are also known as controlled or illicit drugs. Note: Food is excluded from this definition.