<P> 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 major depression . Testing, however, may be done to rule out physical conditions that can cause similar symptoms . Major depression should be differentiated from sadness, which is a normal part of life and is less severe . The United States Preventive Services Task Force (USPSTF) recommends screening for depression among those over the age 12, while a prior Cochrane review found that the routine use of screening questionnaires have little effect on detection or treatment . </P> <P> Typically, people are treated with counseling and antidepressant medication . Medication appears to be effective, but the effect may only be significant in the most severely depressed . It is unclear whether medications affect the risk of suicide . Types of counseling used include cognitive behavioral therapy (CBT) and interpersonal therapy . If other measures are not effective electroconvulsive therapy (ECT) may be tried . Hospitalization may be necessary in cases with a risk of harm to self and may occasionally occur against a person's wishes . </P> <P> Major depressive disorder affected approximately 216 million people (3% of the world's population) in 2015 . The percentage of people who are affected at one point in their life varies from 7% in Japan to 21% in France . Lifetime rates are higher in the developed world (15%) compared to the developing world (11%). It causes the second most years lived with disability after low back pain . The most common time of onset is in a person in their 20s and 30s . Females are affected about twice as often as males . The American Psychiatric Association added "major depressive disorder" to the Diagnostic and Statistical Manual of Mental Disorders (DSM - III) in 1980 . It was a split of the previous depressive neurosis in the DSM - II which also encompassed the conditions now known as dysthymia and adjustment disorder with depressed mood . Those currently or previously affected may be stigmatized . </P> <P> Major depression significantly affects a person's family and personal relationships, work or school life, sleeping and eating habits, and general health . Its impact on functioning and well - being has been compared to that of other chronic medical conditions such as diabetes . </P>

When was major depressive disorder added to the dsm