A Brief Review on the Etiology of Depression

Depression is a common disorder both in men and women, although its occurrence in women is higher. Women tend to encounter this disorder about two times more than men. The prevalence of depression during life span both in men and women would be about fifteen percent [1-3]. Two different types of depression would be endogenous and reactive ones and in both types, genetic and environmental factors are responsible for the occurrence of the disorder. Although there are various genes involved in affective disorders, specific genes which can be responsible for the occurrence of depression have not been identified. Environmental factors and also psychological ones play an important role in the development of depression. Depressive cognitions are very important in developing depression.

Learned helplessness is the important example of the role of depressive cognitions in the development of depression in which the affected individuals have developed this sense that they have no control on the events which will occur in their lives [4]. Since depressive cognitions have important role in developing depression, cognitive therapies can play an important role in the treatment of depression. Memory deficits including working and episodic ones can be seen in depression. Psychomotor retardation is also common in depression. Planning, problem solving and sustained attention are also affected in depression. In cognition and attention dysfunction in depression, perceiving emotionally negative neutral stimuli is very much higher than positive ones [5]. All of these findings suggest the important role of cognitive therapy in the treatment of depression. In evaluation of etiologies for developing depression, paying attention to the neurochemical factors is of importance. Reduced serotoninergic function and also reduced monoamine transmission are two important theories about the development of depression. The effectiveness of using selective serotonin reuptake inhibitors and tricyclic antidepressants in the treatment of depression, supports both serotonin and monoamine theories in the occurrence of depression. In studying the etiology of depression, considering various factors like genetic, environmental and also neurochemical ones is of importance and it leads to make better treatment plans in clinical settings.

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