ORIGINAL ARTICLE Do changes in subjective sleep and biological rhythms predict worsening in postpartum depressive symptoms? A prospective study across the perinatal period Elizabeth M. Krawczak 1,2 & Luciano Minuzzi 1,2,3,4 & Maria Paz Hidalgo 5,6 & Benicio N. Frey 1,2,3,4 Received: 7 August 2015 /Accepted: 15 February 2016 # Springer-Verlag Wien 2016 Abstract Abnormalities of sleep and biological rhythms have been widely implicated in the pathophysiology of major de- pressive disorder (MDD) and bipolar disorder (BD). However, less is known about the influence of biological rhythm disruptions across the perinatal period on postpartum depression (PPD). The objective of this study was to prospec- tively evaluate the relationship between subjective changes in both sleep and biological rhythms and worsening of depres- sive symptoms from pregnancy to the postpartum period in women with and without mood disorders. Eighty-three partic- ipants (38 euthymic women with a history of a mood disorder and 45 healthy controls) were studied. Participants com- pleted subjective assessments of sleep (Pittsburgh Sleep Quality Index), biological rhythm disturbances (Biological Rhythms Interview of Assessment in Neuropsychiatry), and depressive symptoms (Edinburgh Postnatal Depression Scale) prospectively at two time points: third trimester of pregnancy and at 6–12 weeks postpartum. Multivariate regression anal- yses showed that changes in biological rhythms across the perinatal period predicted worsening of depressive symptoms in both groups. Moreover, women with a history of a mood disorder showed higher levels of sleep and biological rhythm disruption during both pregnancy and the postpartum period. These findings suggest that disruptions in biological rhythms during the perinatal period increase the risk for postpartum mood worsening in healthy pregnant as well as in pregnant women with a history of mood disorders. Keywords Biological rhythms . Mood . Postpartum . Pregnancy . Sleep Introduction Postpartum depression (PPD) is an ongoing societal health problem. Whereas between 7 and 15 % of women in the gen- eral population develop PPD (Gavin et al. 2005;O’Hara and McCabe 2013; Serhan et al. 2013), women with history of a mood disorder are at an even greater risk for its development (O’Hara and McCabe 2013; Robertson et al. 2004; Wisner et al. 2002). PPD confers negative outcomes on mothers and their families, which are long lasting if left untreated. For instance, mothers suffering from PPD may experience undermined confidence in the care for their infant, a distorted sense of responsibility and, in more severe cases, infanticide ideation (Barr and Beck 2008). Children of mothers who suf- fered from a depressive episode in the postpartum period are at greater risk for the development of subsequent affective, be- havioral, and cognitive problems (Sellers et al. 2013; Verbeek et al. 2012). PPD also places stress on marital relationships, which may result in greater family dysfunction (Faisal-Cury et al. 2013; Piteo et al. 2013). Notably, a number of studies * Benicio N. Frey freybn@mcmaster.ca 1 MiNDS Neuroscience Graduate Program, McMaster University, Hamilton, Canada 2 Women’ s Health Concerns Clinic, St. Joseph’ s Healthcare Hamilton, Hamilton, Canada 3 Mood Disorders Program, St. Joseph’ s Healthcare Hamilton, Hamilton, ON, Canada 4 Department of Psychiatry and Behavioural Neurosciences, McMaster University, 100 West 5th Street, Suite C124, Hamilton, ON L8N 3K7, Canada 5 Department of Psychiatry, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil 6 Laboratorio de Cronobiologia HCPA/UFRGS, Porto Alegre, RS, Brazil Arch Womens Ment Health DOI 10.1007/s00737-016-0612-x