This paper looks at depression, a mental disorder affecting people of all ages from many walks of life. It examines the current
research on its main causes and describes the four major types of depression that are known of today,
clinical, bipolar disorder or manic depression, SAD (Seasonal Affective Disorder) and chronic depression, all of which have a varying detrimental effect on the person they are acting upon. It shows how the type of depression a person has is usually determined by a careful study of his/her background and the symptoms they exhibit on a regular basis. It also discusses methods of diagnosis such as psychological evaluation as well as methods of treatment such as
psychotherapy, medication or antidepressants and exercise.