Freud, Bowlby and McWilliams formulate different approaches to the etiology of depression, each of which emphasizes different players as determinants of depression. Freud explains the disposition of depression as a series of internal psychic measures that prevent the self from accusing the love object by turning the hatred against part of the self. Bowlby explains adult depression as childhood depression caused by actual attachment disruptions that are carried over to adulthood. McWilliams emphasizes how childhood abnormal circumstances translate into inner psychological formulation of self guilt and self “badness” which then promote the adaptation of different defenses to maintain the existing inner distorted beliefs.
According to Freud, the etiology of depression is rooted in the unconscious ambivalence inherent in significant relationships. Each significant relationship with a love object is bound to be ambivalent – between love and hate, between a wish to love and be loved and a fear to be abandoned or to abandon. Injury and/or disappointment occur in situations of loss of the love object (separation from boy-/girl-friend), which strengthen the hatred (part of the ambivalence) towards the love object. Since experiences of hatred towards the love object induce intolerable anxiety, the psychic in a series of steps would transfer the accusing/hatred cathexis to part of the ego. Thus the libidinal cathexis now withdraws into the ego in a way that one part of the ego is identified with the abandoned object. The self, this way, openly and consciously avoids the hate to the real significant object (which is anxiety inducing) and turns the hatred against the self - the substitute object within the self.
Bowlby conceptualized that the origin of adult depression is a re-activation of an earlier response to separation or loss of the object’s love. Child response mechanisms to unexpected actual early experiences of separation from parents (especially the mother) or the loss of the object’s love as experienced by the child, will maintain their grave intensity and would automatically repeat themselves in a future adult separation. According to Bowlby the actual experiences of loss in childhood may be prolonged separations from parental figures or shifts in the love of the mother such as when a new baby arrives. Those experiences and the child’s unresolved responses to them would create a persistent tendency to develop psychological depression as adults whenever experiences of loss occur.
McWilliams explains depression as unprocessed childhood circumstances and parental attitudes that result in an inner belief of “badness” (“I am a bad person”) and guilt (“I deserve everything bad that happens to me”). In order to deal with that negative self-perception the individual would adopt several defense mechanisms to maintain the negative self perception. The actual circumstances may be both actual-loss-oriented such as divorce or grief and psychological-loss-oriented such as premature push to achieve individuation or parental criticism of the wish for proximity or severe guilt-inducing communications. Successful processing of a child’s inner feelings within the family context, may reduce the risk of developing distorted perceptions, and therefore decrease the probability of later depression.