Depression often requires treatment. Control studies show that modern anti-depressive medicines work. A depressed person has an all pervasive feeling of sadness. There are feelings of worthlessness, inadequacy, and incompetence which hound the patient daily. They can't think normally and they don't calculate correctly.
Depressed persons isolate themselves by withdrawing from friends and families.
There is no laboratory test to make this diagnosis. There are, however, score sheets which reliably differentiate reactions to sad news and grief from depression. Simple grief should only last about three months. After that, consultation is recommended. Treatment given by capsules, such as Desipramine or Nortriptyline, works extremely well.