definition please

Depression ranges in seriousness from mild, temporary episodes of sadness to severe, persistent depression. Doctors use the term "clinical depression" to describe the more severe, persistent form of depression also known as "major depression" or "major depressive disorder." Signs and symptoms of clinical depression may include:

* Loss of interest in daily activities
* Persistent sadness or feeling of emptiness
* Sleep disturbances
* Significant weight loss or gain
* Loss of concentration
* Fatigue
* Suicidal thoughts or behavior

For most forms of depression, symptoms improve with psychological counseling, antidepressant medications or a combination of the two. Antidepressants can relieve symptoms of depression, while counseling may help you cope with ongoing problems that may trigger or contribute to depression.