Working Memory During Late Pregnancy: Associations With Antepartum and Postpartum Depression Symptoms

Abstract

Background: Few studies, with conflicting results, report on the association between memory performance and depressive symptoms during the perinatal period. In this study, we aimed to evaluate whether memory performance during late pregnancy is associated with antepartum (APD) and postpartum depression (PPD) symptoms.

Method: We conducted a prospective follow-up of 283 pregnant women, nested within a large cohort of women enrolled in the BASIC study in Uppsala University hospital between 2009 and 2019. The Wechsler Digit Span Task (forward-DSF, backward-DSB and total score-DST) was performed to evaluate short-term memory/attention (DSF) and working memory (DSB) around the 38th gestational week; the Edinburgh Postnatal Depression Scale (EPDS), evaluating depressive symptoms, was filled out at 17, 32, 38 gestational weeks, as well as at 6 weeks postpartum. Unadjusted and multivariate logistic regression was used to assess the association between performance on the Digit Span Task and outcome, namely depressive symptoms (using a cut-off of 12 points on the EPDS) at 38 gestational weeks, as well as at 6 weeks postpartum.

Results: APD symptoms were not significantly associated with DSF (p = 0.769) or DSB (p = 0.360). APD symptoms were significantly associated with PPD symptoms (p < 0.001). Unadjusted regression modeling showed that DSF in pregnancy was a significant predictor of PPD symptoms (OR 1.15; 95% CI, 1.00, 1.33, p = 0.049), and remained a significant predictor when adjusted for confounders (education and feeling rested at assessment; OR 1.21, 95% CI 1.03, 1.42, p = 0.022). DSF was a predictor of PPD symptoms only for women without a pre-pregnancy history of depression (OR 1.32; 95% CI 1.04, 1.67, p = 0.024) and also those without APD (OR 1.20, 95% CI 1.01, 1.43, p = 0.040).

Conclusion: There was no significant association between working and short-term memory performance and APD symptoms. Among all women, but especially non-depressed earlier in life and/or at antepartum, those scoring high on the forward memory test, i.e., short-term memory, had a higher risk for PPD. Future studies are required to further explore the pathophysiology behind and the predictive value of these associations.

Keywords: Edinburgh Postnatal Depression Scale; antepartum depression; postpartum depression; short-term memory/attention; working memory.

Figure 1

The Figure represents the Direct Acyclical Graph (DAG) depicting hypothesized associations between the main study variables, pertaining mostly to Aim 2. Antepartum Depression, education and feeling rested at assessment, according to DAG system, are the variables of interest in the association of Digit Span Task with Postpartum Depression. According to the DAG model, we have adjusted for education and feeling rested at assessment, and stratified for Antepartum Depression.

Figure 2

The figure presents the scatterplots showing the association between Edinburgh Postnatal Depression Scale (EPDS) (depression) score at 6 weeks postpartum (6 wpp) and memory performance on Digit Span Task stratified by having symptoms of antepartum depression or not. DSF, Digit Span Forward; DSB, Digit Span Backwards; DST, Digit Span Total which is the sum of DSF and DSB.