According to the NHS, around one person in a hundred is diagnosed with a mood disorder in the UK at some point in their lives. Psychoanalytic theory examines the underlying mental processes of the mind (i.e., id, superego and ego) which lead to mood disorders like depression.
Often referred to as the father of psychoanalytic theory, Freud defined depression in terms of a person experiencing a real or imagined loss. As a result, a person may develop guilt, shame or self-hatred and ultimately blame herself.
Once a person develops shame or guilt as a result of a perceived "loss," it can often lead her to carry unresolved conflicts throughout life that can negatively impact relationships. Once a she develops internal and interpersonal conflicts, self-esteem plummets and depression looms.
Mourning and Melancholia
Freud's Mourning and Melancholia, published in 1917, further shaped his views of depression. According to Freud, the loss of an "object" in a depressed individual originated due to unconscious internal processes whereas mourning an object of "loss" (i.e., death of a loved one) was more external and conscious. Therefore, melancholia or depression forces a person's ego to remain in a state of flux or self-induced purgatory (i.e., loss of the self).
A German psychoanalyst and student of Sigmund Freud, Abrahams considered depression a result of fixation which can occur during a person's psychosexual development. For example, if a child develops an oral fixation during childhood, there would be a greater chance of depression in later life.
A pioneer in object relations theory, psychoanalyst Melanie Klein believed a person developed depression due to an inability to release the feeling of the initial real or imagined loss of an object. If a person can't resolve the feeling of loss, the ego resorts to defence mechanisms (i.e., denial or "splitting").