0625 Sleep when the baby sleeps? The effect of daytime nap behaviors on postpartum depression severity: a stress buffering hypothesis

Abstract Introduction The early postpartum is a time of expected maternal sleep loss, normalized as part infant care. While short duration and disrupted nocturnal are posited risk factors for depression (PPD), the role daytime remains less understood, despite widespread recommendation that mothers when their baby sleeping. This study examined associations between napping, stress, longitudinal PPD in sample healthy first-time mothers, using prospective ambulatory field design. Methods Fifty primiparous women (62% non-White; mean age=32 years) without history disorders or psychopathology completed 10-days (9-nights) actigraphy diaries at week 6. Sleep variables included nighttime efficiency, nap frequency, timing duration. Participants 3-days superimposed ecological momentary assessment (EMA) rating naturalistic infant-related stressors (task demand; effort-reward-imbalance) four daily intervals. Hierarchical mixed models tested whether characteristics predicted lower levels (via Edinburgh Postnatal-Depression Scale - EPDS) 6-weeks, 8-weeks, 3-months postpartum. Time-varying within-person covariates time-of-day, baseline anxiety Generalized-Anxiety-Disorder-7 scores), previous night sleep. To test putative stress-protective we pre-post differences EMA ratings. Results Sixty percent (n = 30/47) napped regularly (>3x/1 week, 1-5 PM, < 90 min by both diary actigraphy), 80% these naps “intentional.” Women with greater regularity 6-weeks had all timepoints (Betas -2.4(1.6); -1.4(.5), -.5(.01) ps<.001, respectively), an increase symptoms postpartum, compared to non-nappers [Beta(SE)=-1.2 (.5); R^2=.21; p<.001]. At regular nappers reported stress post-nap (effort-reward-imbalance; demand) [Beta(SE)=-6.3(1.4); 1.2(.12,), R^2=.27, .32, respectively; ps<.01]. Conclusion demonstrates contemporaneous mood-protective perinatal sample, 24-hr objective coupled assessments stressors. Moreover, results provide support protective on development over time. Among new who nap, lowered may be one pathway through which buffers against severity. Support (if any) NIMH-1R36MH118000-01, CTSI89431, T32-HL007713