Title: Authors: Date: Room: Abstract contents Paper 1: [S4- poster] A longitudinal study of postpartum depression: Multilevel growth curve analyses of emotion regulation strategies, breastfeeding self- efficacy and social support Haga, Silje Marie (1,2); Ulleberg, Pål (2); Slinning, Kari (1); Kraft, Pål (2); Steen, Thorbjørn (3); Staff, Anne Cathrine (3,4) 04/10/2012 09:10:00 to 04/10/2012 18:10:00 S Purpose: Postpartum depression (PPD) is a serious health issue affecting as many as 10-15% of postpartum women. This longitudinal study aimed to explore how psychological variables such as cognitive emotion regulation strategies, breastfeeding self- efficacy (BSE) and dimensions of social support predicted postpartum depressive symptoms (EPDS). Method: The data were collected with web- based survey questionnaires between May 2008 and December 2009, in a sample of 737 new mothers. The same questionnaire was surveyed at three points in time: 6 weeks, 3 months, and 6 months postpartum. Data were analyzed using multilevel modelling (level 1: time points, level 2: person). Results: Results showed that BSE, certain cognitive emotion regulation strategies, perceived available support, and need for support predicted the rate of postpartum depressive symptoms. Only breastfeeding self- efficacy predicted change in postpartum depressive symptoms. Conclusion: This study illustrates the importance of psychological variables with regards to postpartum depressive symptoms. Implications for preventative efforts are discussed.