Answer the following question given this paragraph: 

A drug is any chemical that affects the body’s structure or function. Many drugs, including both legal and illegal drugs, are psychoactive drugs . This means that they affect the central nervous system, generally by influencing the transmission of nerve impulses. For example, some psychoactive drugs mimic neurotransmitters. At the link below, you can watch an animation showing how psychoactive drugs affect the brain. http://www. thirteen. org/closetohome/animation/neuron-main. html.


Q: What word describes any chemical that affects the body’s structure or function?


A:
drug