Major Depressive Disorder, Critical Literature Review

                    Major Depressive Disorder Name Institutional Affiliation              
Major Depressive Disorder             Major depressive disorder which can also be simply called depression is a mental disorder that causes mood changes which result in sadness, sorrow, irritability, and a sense of loneliness for more than two weeks. Other symptoms include lack of interest in activities that are normally enjoyable, low self-esteem, sleeping problems, reduced concentration, eating problems, among several others. The symptoms may be present all the time or may cease for years only to emerge again later.  Major depressive disorder largely affects an individual’s quality of life (Belmaker & Agam, 2008). The prevalence of depression during a lifetime stands at between 7%-12% in men, and 20%-25% in women. Depressive disorders account for 40.5% of all mental illnesses (Papakostas & Ionescu, 2014). Traditionally perceived as a disease of the elderly adults, the major depressive disorder has crossed the age barrier and is affecting both the old and the young. Studies have shown high major depressive disorder occurrence rates among young people, especially of ages between 12 and 20 years. Cases of young people with major depressive disorder increased to 11.5% in 2014 from 8.7% in 2005 (Mojtabai, Olfson, & Han, 2016). It was also revealed that the increase in cases of the major depressive disorder in young people has not been met by an increase in mental treatment of young people. Environmental, psychological, social, and genetic factors have all been associated with the condition. Risk factors include substance abuse, some medications, family history of the disease, lifestyle changes, and chronic illnesses (Egede & Zheng, 2003). Socioeconomic status changes have been associated with the major depressive disorder in the elderly. Unemployment has also been shown to be a popular trigger for the major depressive disorder (Park, Lee, Sohn, Seong, & Cho, 2015). The major depressive disorder is managed using antidepressant drugs, counselling, and electroconvulsive therapy.  This review seeks to find out the relationship between genetic, psychological, and social factors in causing and maintaining major depressive disorder. Biological Causes of Major Depressive Disorder             Genetics has been strongly associated with the major depressive disorder, and various studies have been carried out to shed more light on this topic. Research has shown that major depressive disorder can be genetically inherited. This is the reason why people with major depressive disorder family history are at a higher risk of getting the disease. Studies in monozygotic and dizygotic twins have shown that major depressive disorder has a 37% heritability rate (Belmaker & Agam, 2008).             Serotonin, dopamine, and norepinephrine are the monoamine neurotransmitters associated with the m...