Summary: Changes in the strength of circadian rhythms, the average amount of activity during nighttime rest, and the amount of fragmented sleep a woman experienced during the later stages of pregnancy or following birth were strongly associated with increased risks of developing postpartum depression and anxiety.
Source: McMaster University
A set of parameters including sleep and biological rhythm variables are closely associated with the severity of depressive and anxiety symptoms, starting in the third trimester of pregnancy to the third postpartum month, according to a new study.
The three-month period before and after giving birth is a vulnerable time for women’s mental health. It is estimated that 15 to 18 percent of women experience anxiety and seven to 13 percent experience depression during this peripartum period. In addition, nearly 10 percent of women experience clinical levels of comorbid anxiety and depression during this time.
In the largest observational study to date investigating changes in sleep and biological rhythms during the peripartum period, researchers identified several variables that are linked to depression and anxiety. Most notably, changes in the circadian quotient (the strength of the circadian rhythms), the average amount of activity during nighttime rest, and the amount of fragmentation of nighttime rest were strongly linked to higher depressive and anxiety symptoms.
“Our findings highlight the importance of stabilizing the internal biological clock during the peripartum period to maintain healthy mood and minimize anxiety,” said Benicio Frey, senior author of the study and professor in the department of psychiatry and behavioral neurosciences at McMaster University.
“Given the findings, future efforts should be made to standardize evidence-based interventions targeting these biological rhythms variables identified by our team, either as treatment or prevention strategies.”
Frey and his research team conducted the study from the Women’s Health Concerns Clinic at St. Joseph’s Healthcare Hamilton. This clinic specializes in psychiatric disorders during the peripartum, premenstrual, and perimenopausal periods.
Researchers recruited 100 women, 73 of whom they followed from the start of the third trimester to three months postpartum. They analyzed subjective and objective measures of sleep, biological rhythms, melatonin levels, and light exposure using a variety of tools, including questionnaires, actigraphs (wearable sleep monitors), laboratory assays, and other methods.
Interestingly, the findings indicate that certain biological rhythms variables may be important to depressive symptoms at specific points along the peripartum timeline. For instance, higher fragmentation of nighttime rest was linked to a decrease in depressive symptoms at six to 12 weeks postpartum—a period that tends to coincide with a higher risk of developing postpartum depression.
Longitudinal Changes in Sleep, Biological Rhythms, and Light Exposure From Late Pregnancy to Postpartum and Their Impact on Peripartum Mood and Anxiety
Objective: In one of the largest and most comprehensive studies investigating the link between objective parameters of sleep and biological rhythms with peripartum mood and anxiety to date, we prospectively investigated the trajectory of subjective and objective sleep and biological rhythms, levels of melatonin, and light exposure from late pregnancy to postpartum and their relationship with depressive and anxiety symptoms across the peripartum period.
Methods: One hundred women were assessed during the third trimester of pregnancy, of whom 73 returned for follow-ups at 1–3 weeks and 6–12 weeks postpartum. Participants were recruited from an outpatient clinic and from the community from November 2015 to May 2018. Subjective and objective measures of sleep and biological rhythms were obtained, including 2 weeks of actigraphy at each visit. Questionnaires validated in the peripartum period were used to assess mood and anxiety.
Results: Discrete patterns of longitudinal changes in sleep and biological rhythm variables were observed, such as fewer awakenings (F = 23.46, P < .001) and increased mean nighttime activity (F = 55.41, P < .001) during postpartum compared to late pregnancy. Specific longitudinal changes in biological rhythm parameters, most notably circadian quotient, activity during rest at night, and probability of transitioning from rest to activity at night, were most strongly linked to higher depressive and anxiety symptoms across the peripartum period.
Conclusions: Biological rhythm variables beyond sleep were most closely associated with severity of depressive and anxiety symptoms across the peripartum period. Findings from this study emphasize the importance of biological rhythms and activity beyond sleep to peripartum mood and anxiety.