While the birth of a child is usually a joyous occasion, a significant number of women feel an inexplicable darkness descend on them afterwards. Postpartum depression (PPD) can make childrearing seem an impossible task and it can hamper bonding with the child. Now that there is more awareness of PPD, doctors frequently warn new mothers of the possibility and instruct them to pay attention to symptoms. However, families are still often caught unawares. This problem may be alleviated by a new predictive method developed by Dr. Ilona Yim and discussed in the February issue of the Archives of General Psychiatry.

Previous studies have unearthed a few factors that correlate with the risk of PPD, such as socioeconomic status and weak social support, but these were hard to quantify. Therefore, Dr. Yim searched for an objective chemical marker that would help predict the later onset of PPD.  Working with three hypothesis, she tested the correlation between PPD and cortisol (the stress hormone), ACTH, and placental corticotropin-releasing hormone (pCRH).

Dr. Yim gathered 100 pregnant women and took blood samples at 15, 19, 25, 31, and 37 weeks of gestation and administered a questionnaire that detects PPD symptoms. Dr. Yim did not find any correlation between PPD and cortisol or ACTH, but she did find a significant one with pCRH. The pCRH correlation was extremely strong at the 25 week mark; approximately three-fourths of the women who went on to develop PPD, of which there were 16, would have been identified by this predictor, with fairly few mistaken identifications.

This discovery is heartening because it means that families will have a much clearer warning to prepare for the frighteningly onset of PPD. Gestational diabetes tests are already performed at 25 weeks with a blood test, so the additional sampling of pCRH levels would be quite simple. Women who have this advance warning will not have to struggle for long weeks wondering why they are depressed when they should be happy. Instead, upon detecting the very first symptom, they can begin relying on the therapy and support that they have already prepared.