If Max ingests a small amount of a drug, he may be livelier and more outgoing at a party. If he then continues to consume more of the drug, he will find that the drug actually slows his system down and impairs his thinking. The drug in this case is ___.

drug in this case is alcohol

Explanation:

Alcohol is a form of drug known as depressant and cause depression, which can slow down the activity of the nervous system. Alcohol is a central nervous system depressant drug that gradually inhibits brain function, which in turn impairs the functioning of the central nervous system. Alcohol is a depressant that also exhibits stimulant effects, which is said to be useful for stimulation when taken in small amounts. The person acted to be 'alive and more outgoing' at a party, which should be said for excitement, and that the slowing down of the drug was the effect of depression.