Is positive affect in pregnancy protective of postpartum depression?

Objective: To investigate the predictive/protective role of negative affect/positive affect in late pregnancy on the outcome of postpartum depression. Methods: A total of 491 pregnant women participated in the study. The participants were asked to fill out a series of questionnaires, which included the Profile of Mood States, the Beck Depression Inventory-II, psychosocial variables and socio-demographic characteristics and were asked to participate in a psychiatric interview. After delivery, 272 mothers participated again in the study and filled out a similar series of questionnaires. Results: Negative affect was associated with more intense depressive symptomatology, more self-perceived stress, lower self-reported social support, lower quality of life and perception of having a more difficult infant. By contrast, positive affect was negatively associated with these variables. Negative affect in late pregnancy increased the likelihood of experiencing postpartum depression (DSM-IV/OR = 2.1, 95%CI = 1.3-3.4, p =.003; ICD-10/OR = 2.1, 95%CI = 1.5-3.0, p <.001), while positive affect increased the odds of not having this condition (DSM-IV/OR = 2.0, 95%CI = 1.5-2.7, p =.042). Conclusion: In pregnancy, negative affect was a predictor of postpartum depression, whereas positive affect showed a protective role. Future studies are required to explore whether psychotherapeutic strategies focusing on decreasing negative affect and enhancing positive affect in the last trimester of pregnancy can reduce the risk of postpartum depression.