In the course of a normal day, everyone has small emotional ups and downs. These are a part of normal life. For example, on awakening, a person may feel tired. There is a normal range of emotions that a person experiences from time to time.
Amphetamines cause euphoria at first.
As the drug effects wear off, the emotions swing back the other direction. The person feels far worse than usual as the pendulum of emotions swings back in the other direction. The terrible fatigue and depression may prompt the drug abuser to take more of the amphetamine. Over time, vast emotional swings and preoccupation with drug use prevent the amphetamine user from leading a normal life. Folb S. A five hour drug information program for middle school students.