Original article A prospective longitudinal study of the impact of early postnatal vs. chronic maternal depressive symptoms on child development A.-L. Sutter-Dallay a,b,c, *, L. Murray d , L. Dequae-Merchadou e , E. Glatigny-Dallay c , M.-L. Bourgeois a , H. Verdoux a,c,f a University Victor Segalen Bordeaux 2, Bordeaux, France b EA 4139, IFR of Public Health, Bordeaux, France c University Department of Psychiatry, Charles Perrens Hospital, Bordeaux, France d School of Psychology, University of Reading, Reading, UK e INSERM U 593, IFR of Public Health, Bordeaux, France f INSERM U 657, IFR of Public Health, Bordeaux, France 1. Introduction Postnatal depression (PND) is one of the most common complications of childbearing, affecting 10–15% of mothers [9,27,43], and represents a major public health problem [4,52]. Depression at any period may result in deterioration in interper- sonal relationships. Postnatally depressed mothers are particularly prone to present with impairments in patterns of social interac- tions [6,19,35], with potentially adverse consequences for their infants [49,50]. Thus, young infants are highly sensitive to the emotional quality of their carer’s communication, and mothers play a key role in mediating the effects of the wider environment on their child’s development [17,23,32,34,40,54]. Over the past 15 years, a body of prospective research has accumulated examining associations between PND and adverse child outcome. With regard to child cognitive functioning, the study of Sharp et al. [46], continued by Hay and colleagues [25], found a link between PND and child cognitive poor functioning at both 4 and 11 years. Cogill et al. [11] also reported that 4-year-old children of PND mothers had significantly poorer cognitive performance compared to those of women without PND. Finally, Black et al. [3] found infant Mental Development Index scores at 12 months to be associated with concurrent maternal depression. By contrast, other studies have failed to identify a significant association between PND and child cognitive outcome [7,14,20,28,35,36,39,41,44]. Some of these latter studies suggest that the association between PND and children’s cognitive outcome may be related to the severity, persistence or recurrence of maternal depressive symptoms beyond the postpartum period. For example, Petterson and Albers [44] found that the cognitive development of children of mothers with severe PND was only negatively affected when the mother was also depressed at 3 years. Similarly, Kurstjens and Wolke [28] reported that boys of postnatally depressed mothers had lower cognitive scores only when maternal PND was followed by subsequent depression. European Psychiatry 26 (2011) 484–489 A R T I C L E I N F O Article history: Received 17 September 2009 Received in revised form 11 May 2010 Accepted 12 May 2010 Available online 10 July 2010 Keywords: Postnatal depression Child development Cohort Sensitive period A B S T R A C T Background: Few studies of the effects of postnatal depression on child development have considered the chronicity of depressive symptoms. We investigated whether early postnatal depressive symptoms (PNDS) predicted child developmental outcome independently of later maternal depressive symptoms. Methods: In a prospective, longitudinal study, mothers and children were followed-up from birth to 2 years; repeated measures of PNDS were made using the Edinburgh Postnatal Depression Scale (EPDS); child development was assessed using the Bayley Scales II. Multilevel modelling techniques were used to examine the association between 6 week PNDS, and child development, taking subsequent depressive symptoms into account. Results: Children of mothers with 6 week PNDS were significantly more likely than children of non- symptomatic mothers to have poor cognitive outcome; however, this association was reduced to trend level when adjusted for later maternal depressive symptoms. Conclusion: Effects of early PNDS on infant development may be partly explained by subsequent depressive symptoms. ß 2010 Elsevier Masson SAS. All rights reserved. * Corresponding author. Po ˆle universitaire de psychiatrie de l’adulte, ho ˆpital Charles-Perrens, re ´ seau de psychiatrie pe ´ rinatale, 121, rue de la Be ´ chade, 33076 Bordeaux cedex, France. Tel.: +33 5 56 56 17 82; fax: +33 5 56 56 17 68. E-mail address: alsutter@ch-perrens.fr (A.-L. Sutter-Dallay). 0924-9338/$ – see front matter ß 2010 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.eurpsy.2010.05.004