Major depressive disorder is characterized by a variety of symptoms. Some of these symptoms express themselves through an individual's thoughts or emotional state. Other symptoms of depression express themselves through how an individual functions in her life; and these types of changes are called the neurovegetative signs of depression. There are eight neurovegetative signs of depression.
A significant increase or decrease in appetite and/or weight is considered to be a neurovegetative sign of depression. If there is a change in weight, a change of more than 5 percent in one month is required in order to meet this criterion.
Difficulty with concentration or with making decisions is another sign. Reports of problems with memory are common. In order for this symptom to meet diagnostic criteria, it would need to occur nearly every day.
Excessive tiredness or low energy is a frequent symptom of depression. A person might report feeling exhausted after minimal activity and can exhibit reduced efficiency.
A depressed person may feel guilty or worthless, and spend much time revisiting previous missteps and blaming himself for negative events or outcomes. These feelings may be excessive or inappropriate. In some cases, they may stem from delusional thinking, such as a person believing that she is responsible for a destructive earthquake.
Loss of Interest or Pleasure
Anhedonia is the loss of interest in activities or events that were once found to be enjoyable. This symptom may be reported by the depressed person or observed by those around him. Loss of sexual interest or pleasure is sometimes reported.
Psychomotor Retardation or Agitation
Depressed people sometimes exhibit a significant decrease in their physical movement, or a significant increase. With psychomotor retardation, a person may be observed to move slowly or less often, speak slowly, and think more slowly. Psychomotor agitation is characterized by faster or increased movement or speech. These changes must be observed by others.
Another neurovegetative sign of depression is a marked increase or decrease in sleep patterns. Insomnia is more common than hypersomnia. The most common sleep disturbance involves waking up in the middle of the night and having difficulty falling back asleep.
Repeated thoughts of death may or may not be accompanied by serious intent or a plan.