An individual who has been using a drug for an extended period of time suddenly finds himself unable to secure more of the drug. he acts nervous and irritable and is hyperactive. he seems almost desperate to find more of the drug, but experiences no sickness, pain, or other outward physical discomfort. based on his behavior, what drugs might he possibly have been using? explain your answer.

Cocaine. When an individual uses a stimulant, they become hyperactive and paranoid. They appear nervous and are always looking over their shoulders and believe someone is after them. Cocaine is a powerful central nervous stimulant and with prolonged use comes hallucinations and paranoid delusions. People who use cocaine do not suffer from a withdrawal other than craving the drug over and over.
Read chapter 11 of Criminalistics: An Introduction to Forensic Science by Richard Saferstein.