Loss of energy 7. Feelings of worthlessness or guilt 8. Decreased ability to concentrate 9. Recurrent thoughts of death or suicide Adapted from the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. One of the paradoxes that makes depression hard to understand is the wide range of symptoms.
Depression is a common, serious illness.
Because it is so common, because it can be treated, and because it can be fatal, everyone needs to be familiar with its symptoms, which are highly variable. But two people can be equally depressed and have few common symptoms. This is because a diagnosis requires that a patient experience at least five symptoms out of a list of nine. Symptoms of Depression Feeling sad, depressed, or blue all or most of the time. Loss of interest in the things you used to enjoy.