A longitudinal study of hypomania and depression symptoms in pregnancy and the postpartum periodHeron et al. (2009) Bipolar Disorders, 11 410-417

We know that childbirth is a powerful trigger of severe episodes of bipolar disorder, but there has been little research into whether it also triggers milder bipolar symptoms or ‘hypomania’. Hypomanic symptoms, known as ‘highs’, include feeling more elated than usual, more talkative than usual, more active than usual, thoughts racing, feelings of being an especially important person, needing less sleep and problems with concentration.  This study investigated mood during pregnancy and after delivery to see whether childbirth is a time of increased risk for hypomanic symptoms in the general population.

A total of 446 women were recruited at 12 weeks of pregnancy and asked to complete two questionnaires (the Highs Scale and the Edinburgh Postnatal Depression Scale) at three time points:  the first at approximately 12 weeks of pregnancy, the second at one week after delivery and the third at 8 weeks after delivery. 

Hypomanic symptoms were found to be significantly increased in the early postpartum period. The number of cases of ‘the highs’ increased from 1.4% antenatally to 11.7% in the postpartum week (an eightfold increase), and decreased again by 8 weeks postpartum to an intermediate rate of 4.9%.  Cases of depression did not change significantly from pregnancy to the postpartum period.

These findings indicate that childbirth is a potent trigger not only of severe manic symptoms in women with a vulnerability to bipolar disorder, but also of hypomanic symptoms in women from the general population. 

We hypothesise that mild hypomania could be a normal and adaptive state after having a baby (e.g. the need for less sleep and increased energy and confidence could offer advantages to a mother and her infant).  However the same process could put some women at increased risk of postpartum psychosis.  Studying the postpartum highs and bipolar spectrum symptoms in the general population might help us better understand the biological, obstetric and psychosocial triggers of postpartum psychosis.