In depression, the functionality of the body also declines. These changes in appetite, sleep, and activity levels can take many forms. Some depressed patients tend to lose their appetite, but others find themselves craving for more food, perhaps even binge eating. Some depressed patients desire to sleep all throughout the day. Others find it difficult to sleep and may experience a form of insomnia known as early morning wakening, in which they awaken at 3 or 4 A.M every morning and cannot go back to sleep.
Behaviorally, many depressed patients are slowed down, a condition referred to as psychomotor retardation. They walk more slowly, and talk more slowly and quietly gesture more slowly. They tend to have more accidents, because they cannot react to crises as quickly as necessary to avoid them. Many of them lack energy and report feeling constantly fatigued. A group of depressed people has psychomotor agitation instead of retardation. They feel physically agitated. They cannot sit still, and may move around or fidget aimlessly.
A few depressed people experience extreme behavioral disturbances referred to as catatonia. This is a collection of unusual behaviors that range from complete lack of movement to excited agitation. One form of catatonia is catalepsy. People with this condition seem to be in a trancelike state, and their muscles assume a waxy rigidity, so that they tend to remain in any position in which they are placed. Catatonia can also involve excessive motor activity, such as fidgeting hands, tapping the feet, rocking back and forth, and pacing, all without any apparent purpose. People with catatonia may show disturbances in their