Major depressive disorder or MDD, clinical depression which is a condition that has been known as the "common cold" of psychological disorders - an phrase that effectively describes its pervasiveness but not its seriousness. It is described to be an episodic disorder, meaning, it occurs in episodes that come and go. Major Depressive Disorder is most commonly influence ages 18 and 45, however, can begin in childhood or old age. Canadians experience major depressive disorder at some point throughout their lifetime, 12 percent of Canadian adults and 13 percent of U.S adults have experienced a depressive disorder. (2014, Myers, David G. "Disorders." Exploring Psychology. New York. 470-471.) However, less than half the people who experience these effects, are treated for medical and/or psychological help, and given an official diagnosis. Major depressive disorder occurs 5.8 percent of men and 9.5 percent of women, and is likely to develop into the second leading source of temporary disability in the world by 2020, according to the World Health Organization. For instance, symptoms may be accompanied with low mood, sleep disturbances, changes in appetite, difficulty concentrating, lethargy, grief, feelings of worthlessness, diminished interest in activities, and social isolation. Also, can experience psychosis and hallucinations, with that being said, Major Depressive Disorder is characterized by one or more major depressive episodes (i.e. at least 2 weeks of depressed mood and/or loss of awareness accompanied by at least 4 other symptoms of depression). As a result, major depressive disorder occurs frequently to those who are prone to stress - such as the unemployed, people working in a monotonous, dull, or unfulfilling work environment, poor socio-economic status families or an individual and end of a romance.
As anxiety develops, the response to the threat of future loss, an example, such as, job loss or job seeking, severe illness or death of a loved one, divorce or separation, growing up in a dysfunctional family, and changes of environment, like one moving to a new place.