If affects the way you eat and sleep, the way you feel about yourself, and the way you react to and think about the people and things around you.
Symptoms can last for weeks, months, or years.
There are many types of depression, and they vary with the number of symptoms, their severity and persistence. The causes of depression are not fully understood. Depression may be triggered by stress, tension, a traumatic life event, chemical imbalances in the brain, thyroid disorders, upset stomach, headache, nutritional deficiencies, poor diet, the consumption of sugar, lack of exercise, and serious physical disorder, or allergies. One of the most common causes of depression is food allergies. Heredity has been shown to be a significant factor in the occurrence of depression.