Objective: To better understand mood changes in pregnancy and postpartum, we studied mood instability in a group of perinatal women and in a group of normally menstruating non-pregnant women.
Methods: Perinatal women (n = 45) completed the Edinburgh Postnatal Depression Scale at 16 weeks' and 30 weeks' gestation and again at four weeks postpartum. Immediately after completing the Edinburgh Postnatal Depression Scale, participants also completed mood diaries with separate visual analogue scales for depressed, irritable, anxious, and euphoric/activated moods. This was done twice daily for one week. A comparison group of 31 non-perinatal women without depression or premenstrual symptoms completed identical mood diaries for seven consecutive weeks. Mood instability was represented by the mean square successive difference statistic.
Results: Perinatal women showed higher mean levels of depressed, irritable, anxious, and high mood instability than the non-perinatal women. The findings held when pregnant women who were depressed were removed from the comparison, except that the difference in depressed mood instability was no longer significant.
Conclusion: Wider fluctuation in mood in pregnant and postnatal women is consistent with the common belief that perinatal women are moodier than non-perinatal women.