The study from SLEEP 2022 is the first to explore directionality of sleep-stress relationships in a sample of perinatal women.
Sammy Dhaliwal, PhD, MSs, Perelman School of Medicine, and a group of investigators conducted a study to test the directionality of the relationship between habitual nighttime sleep parameters and daytime stress ratings during the perinatal period.
The research was presented at Associated Professional Sleep Societies (SLEEP) 2022 Annual Meeting.
Pregnancy often brings pronounced sleep disturbance. 85% of women endorse shorter and more fragmented sleep patterns during the gestational process.
Investigators noted that new-onset antenatal depression (AND) is a known risk factor for postpartum depression, but that its etiology remains less understood, despite well-established evidence that incidence is the same among healthy first-time mothers as compared to women with established riskfactors. Particularly ones inclusive of family or personal history of psychopathology.
Antenatal depression may be provoked by disrupted sleep due to heightened daily stress, investigators suggested. Daily stress appraisals could be a critical pathway leading to this.
"This is the first study to explore directionality of sleep-stress relationships in a perinatal sample," they wrote.
The prospective amulatory field study design included 50 primiparous women who had no history of sleep disorders or pychopathology. Over the span of 10 days and 9 nights of actigraphy inviduals completed sleep diary entries.
Additionally, they engaged in 3 days of superimposed ecological momentary assessments (EMA) at 4 intervals throughout the day rating stress, positive, and negative affect.
Analyses were designed to examine negative affective responses to social conflict and task-based demand during the EMA time period. This was assessed at the within-person and between-women levels.
Sleep variables included in the investigation were total sleep time, sleep efficiency, sleep onset latency, and sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI).
"Cross-lagged hierarchical mixed models tested directionality of sleep-stress relationship," investigators wrote. "Time-varying covariates included time-of-day, previous day stress for sleep outcomes, and previous night sleep for stress outcomes, at the within-person levels."
Investigators found that following days where greater stress was experienced, the individuals had significantly shorter, less efficient sleep and took longer to fall asleep, according to both diary entries and actigraphy.
After those night of shorter sleep, their negative affective responses to stress were greater. Over the entire assessment period, those who attained shorter, less efficient sleep also experienced great frequency and higher severity stressors, after investigators adjusted for time-of-day, and baseline sleep characteristics, depression and anxiety levels.
Stress was examined as a moderator of the relationship between total sleep time and depression severity due to the bidirectional support, as examined at 36 weeks gestation.
Investigators wrote that this indicated greater stress was the explanation for the relationship between shorter total sleep time and heightened antenatal depression.
The data support the idea that heightened daily stress engenders difficulty initiating and maintaining sleep, shorter duration of sleep and ultimately greater sleep disturbance.
"Bidirectional support for shorter sleep duration and increased stress appraisal was also found," investigators concluded. "The current project provides preliminary evidence for stress 'spill-over' effects (i.e., stress transmission) as a potential mechanism for heightened antenatal depression symptoms."