Sleeping For Two: Evaluating Sleep as a Mediator of the Effect of Cognitive Behavioural Therapy for Insomnia (CBT-I) Delivered in Pregnancy for Postpartum Depression
Date
2022-08
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Abstract
Background: Insomnia and sleep concerns are common during pregnancy and lead to adverse short- and long-term consequences for the pregnant person and their child. Within the general population, poor sleep, including decreased sleep quality and shortened sleep duration, is associated with worse emotion regulation and low mood; these findings also extend into the perinatal period (Vafapoor et al., 2018; Wang et al., 2018). It is unclear whether improving sleep during pregnancy is associated with better mood, and whether these effects persist into the postpartum period. The primary aim of this study is to investigate whether the treatment of insomnia in pregnancy using cognitive behavioural therapy for insomnia (CBT-I) is associated with improved postpartum depression and whether improvements in sleep (insomnia symptoms) following intervention mediate the relationship between CBT-I treatment and postpartum mood. Methods: A two-arm, single-blinded, parallel groups randomized controlled trial (RCT) design was used to evaluate the impact of a 5-week CBT-I intervention compared to a control group among a sample of 62 pregnant people. Participants were eligible if they were pregnant, between 12-28 weeks’ gestation, and had a diagnosis of insomnia. Participants completed structured interviews to assess depression and sleep in addition to other measures of insomnia (objective and subjective reports), sleep quality and duration. Assessments were completed at 12-28 weeks of pregnancy (T1), six weeks after baseline (T2), and six months postpartum (T3). At the (T3), participants completed a battery of questionnaires measuring psychosocial variables such as mood including depressive symptoms and infant sleep. Results: Using a custom mediation model made in PROCESS V 4.0 and SPSS 26.0, findings from the current study found that there was no direct effect of CBT-I in pregnancy on postpartum depression. However, there was a significant indirect effect of CBT-I on postpartum depression at T3 through a serial mediation from sleep at T2 to sleep at T3 while controlling for baseline symptoms of depression, insomnia, and infant sleep at T3. The indirect effect of CBT-I on depression at T3 through sleep at T2 (single mediation), and the individual indirect effect of CBT-I on depression at T3 through depression at T2 (single mediation) were not significant.
Discussion: The current paper aimed to build on the finding that CBT-I in pregnancy reduces postpartum depressive symptoms by trying to understand the mechanism under which CBT-I during pregnancy improves postpartum mood. Findings from this paper suggest that CBT-I leads to sustained improvements in sleep which are associated with lower levels of depression. These results provide further support for the call for increased attention to sleep within the realm of prenatal care and research.
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Keywords
CBT-I, Insomnia, Pregnancy, Sleep, Postpartum depression
Citation
Silang, K. (2022). Sleeping for two: evaluating sleep as a mediator of the effect of Cognitive Behavioural Therapy for Insomnia (CBT-I) delivered in pregnancy for postpartum depression (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.