Major depressive disorder
The cause is believed to be a combination of genetic, environmental, and psychological factors. Risk factors include a family history of the condition, major life changes, certain medications, chronic health problems, and substance abuse. About 40% of the risk appears to be related to genetics. The diagnosis of major depressive disorder is based on the person's reported experiences and a mental status examination. There is no laboratory test for the disorder. Testing, however, may be done to rule out physical conditions that can cause similar symptoms. Major depression is more severe and lasts longer than sadness, which is a normal part of life. Since 2016, the United States Preventive Services Task Force (USPSTF) has recommended screening for depression among those over the age 12, while a 2005 Cochrane review found that the routine use of screening questionnaires has little effect on detection or treatment.
Major depressive disorder-2