Serum cortisol levels are related to moods of elation and dysphoria in new mothers.

Serum cortisol levels were measured in 163 women on the third day after childbirth. Significantly elevated levels of cortisol were found to be associated with the "blues," and significantly lower levels characterized women who exhibited mild hypomania (the "highs"). Low levels of cortisol were independently associated with epidural anesthesia, while elevated levels were related to assisted delivery. There was no significant association with breast or bottle feeding. Changes in serum cortisol were thus found to parallel the mild bidirectional changes in affect that frequently follow childbirth.