Symptoms of depression include a depressed, sad, blue mood, as well as changes in sleep (oversleeping, or difficulty falling and staying asleep), appetite (overeating, or loss of appetite), energy (loss of energy manifesting as sluggishness, or a seeming excess of energy leading to agitation), diminished or lost ability to experience pleasure (anhedonia), reduced sexual drive, reduced concentration and or memory (short term memory), a sense of helplessness, hopelessness or being trapped, frequent thoughts about death, and often a change in the depression with the time of the day (either worse in the morning, or worse in the evening), and social withdrawal. Thus we see changes, or poor regulation in mood, reward, vegetative, reproductive, motor, cognitive, and social spheres.
