Postpartum depression (PPD), with a prevalence of about 10-15% in developed countries, has a major impact on both mother and child. Personality traits, mainly neuroticism, have been associated with affective disorders and in particular postpartum depression.

To examine if neuroticism is associated with depressive symptoms in pregnancy and post-partum, controlling for possible confounding factors.

Since September 2009, all pregnant women in Uppsala, Sweden have been asked to participate in BASIC study, which is a population based, prospective study on mental health during pregnancy and post-partum. Women filled in the Swedish Scales of Personality (SSP), as well as the Edinburg Postnatal Depression Scale (EPDS) in pregnancy week 32. EPDS was also administered 6 weeks and 6 months postpartum. A factor analysis of SSP traits was conducted in our material and the three factor structure comprising neuroticism, aggressiveness and sensation seeking was confirmed. The association between personality traits and depressive symptoms was examined using binary logistic regression. High levels of neuroticism, aggressiveness and sensation seeking were defined as the highest quartile of each factor.

High levels of neuroticism were strongly associated with depressive symptoms during pregnancy as well as at 6 weeks and 6 months post-partum, while aggressiveness and sensation seeking were not. After controlling for confounding factors, such as previous history of depression, employment, education, partner support and breastfeeding, neuroticism remained a significant predictor for depressive symptoms, at all three time-points.

Neuroticism is an independent strong predictor of depressive symptoms during pregnancy and the postpartum period.