A selection of 'drugs', 2000.

This selection of drugs includes sedatives, stimulants and painkillers. Clockwise from left: aspirin, cigarettes (nicotine), sleeping tablets, coffee beans (caffeine) and 'cocaine'. Many drugs work by copying or blocking the effects of naturally occuring chemicals in the brain. The risk to users, however, is that they may become dependent on such drugs, as well as suffering adverse effects on their health from prolonged or excesive consumption. (Note: icing sugar has been used here to simulate the appearance of cocaine.)