Postpartum Depression: An Evolutionary Perspective

There is no common consensus among theorists regarding the nature and purpose of postpartum depression. Evolutionary theorists have proposed that the onset of postpartum depression is an adaptive function that signals a potential fitness cost to the mother i. e. the investment in the child will be cost more than the evolutionary benefits to be gained from rearing this child Many studies have shown that there is a strong correlation between postpartum depression and lack of paternal or social support indicating that when these two variables are absent the mother is more likely to experience postpartum depression. In this paper I hope to outline the evolutionary approach to postpartum depression, discuss the various possible social situations that would predict the absence or presence of postpartum depression and review the cross-cultural literature to see if this evolutionary perspective holds up as a universal across all cultures. Mothers with postpartum depression (PPD) commonly have thoughts of harming their children, exhibit fewer positive emotions and more negative emotions toward them, are less responsive and less sensitive to infant cues, less emotionally available, have a less successful maternal role attainment, and have infants that are less securely attached. PPD is a depressive episode with onset occurring one month postpartum (APA 1994). Postpartum depression (PPD) has been somewhat of an anomaly to the clinical and scientific community. Theories concerning the occurrence of postpartum depression have often failed to account for the cross-cultural differences in the manifestation of PPD. There has been a long standing argument as to whether PPD is a universal disorder or a culture-bound syndrome that appears in some cultures and not others. This paper seeks to understand postpartum depression from a relatively new angle: that of evolutionary theory. Evolutionary theory understands PPD not as a dysfunction, as the above American Psychiatric Association implies, but rather as an adaptive mechanism that signals to a mother that she is suffering or has suffered a social cost which motivates her to evaluate whether to continue to or cease to provide care to her offspring. Intuitively, it sounds odd that such an