Regression is a characteristic sign of certain mental illnesses. It comes from a Latin word meaning to go backward. Doctors use the word to mean a return to a way of thinking or behaving that would normally be characteristic of an earlier period of life. For example, if a 4-year-old child, after the birth of a baby brother or sister, began to act like a baby, doctors would call the child’s behavior regression. However, mentally healthy persons sometimes exhibit regression, as when they play games or daydream.
