A depressed person may gain or lose weight, eat more or less than usual, have difficulty concentrating, and have trouble sleeping or sleep more than usual. He or she may feel tired and have no energy for work or play. Small burdens or obstacles may appear impossible to manage. The person can appear slowed down or agitated and restless. The symptoms can be quite noticeable to others.
A particularly painful symptom of this illness is an unshakable feeling of worthlessness and guilt. The person may feel guilty about a specific life experience or may feel general guilt not related to anything in particular.
If pain and self-criticism become great enough, they can lead to feelings of hopelessness, self-destructive behavior, or thoughts of death and suicide. The vast majority of people who suffer severe depression do not attempt or commit suicide, but they are more likely to do so than people who are not depressed.
The thoughts of people with major depression are often colored by their dark mood. For example, pessimistic ideas may be out of proportion with the reality of the situation. Sometimes, the depressed thinking is distorted enough to be called "psychotic;" that is, the person has great difficulty recognizing reality. Sometimes, depressed people develop delusions (false beliefs) or hallucinations (false perceptions).
Symptoms of major depression include:
Distinctly depressed or irritable mood
Loss of interest or pleasure
Decreased or increased weight or appetite
Increased or decreased sleep
Appearing slowed or agitated
Fatigue and loss of energy
Feeling worthless or guilty
Poor concentration or indecisiveness
Thoughts of death, suicide attempts or plans