Findings suggest that parents, especially ones with a history of depression, should pay close attention to the conditions they create for their infant’s sleep
ANN ARBOR, Mich. – Babies born to depressed moms are likely to suffer from chaotic sleep patterns, which could predispose them to depression later in life, according to a University of Michigan study published in the May issue of the journal SLEEP.
Findings of the study, conducted by U-M sleep expert Roseanne Armitage, Ph.D., are significant because they show that sleep and biological rhythms disturbances persist at least through the first eight months of life in the infants of depressed mothers.
Sheila Marcus, M.D., clinical associate professor of psychiatry at the U-M Medical School, and Heather Flynn, Ph.D., a psychologist and member of the U-M Depression Center Women’s Mood Disorders Program, co-authored the study.
The findings suggest that parents – especially ones with a history of depression – should pay close attention to the conditions they create for their infant’s sleep, says Armitage, leader of the U-M Sleep & Chronophysiology Laboratory team at the U-M Depression Center.
Armitage and her team have shown that insomnia and interupted sleep are strongly linked to depression.
Their research in depressed adults, teenagers and pre-teens led them to expand their research to babies. Infants need a lot more sleep than grownups, but tend to get it in shorter chunks of time throughout the day and night, at least for the first months of life.
Armitage conducted her research with two groups of new mothers and their babies, funded by the Cohen Sleep Research Fund and the Drs. Jack and Barbara Berman Depression Research Fund at the U-M Depression Center.
One group was made up of mothers who sought help for depression during pregnancy from the U-M Depression Center’s Women’s Mood Disorders Program. The other group had no past or current depression. Each group wore devices that measured sleep time at night, light exposure and daytime activity/rest patterns.
The moms wore the devices during the last trimester of pregnancy, and after their babies were born, the team fitted each child with a tiny actigraph at two weeks of age. Information was collected monthly until babies were 8 months old.
Results indicate that infants born to mothers with depression had significant sleep disturbances compared to low-risk infants. The high-risk group took up to 2 hours more to settle for night time sleep, woke up more often and had more daytime sleep than infants who were born to mothers without depression at two weeks and 30 weeks post-partum.
“We think we may have identified a vulnerability in the initial entrainment of sleep and circadian rhythms that may elevate the risk for these children to develop later depression,” Armitage says. “Our task now is to determine if it is modifiable. Can we reverse the effects and reduce the risk of developing later depression by enriching sleep and circadian rhythms in infancy? ”
Infants and toddlers need to nap during the daytime to get all the sleep they need – 11 to 18 hours for newborns in the first two months, 11 to 15 hours for the next 10 months, and 12 to 14 hours from ages 1 to 3 years. And, newborns wake up in the night when they need food.
“But going to bed at the same time, getting up at the same time, establishing rituals around the bedtime helps infants begin to distinguish between night sleep and day sleep,” says Armitage, a professor of psychiatry at the U-M Medical School. “Put the baby in day clothes for naps, and in night clothes for night sleep – babies pick up these cues.”
Parents can also make sure that babies are regularly around bright light during the day, which helps the body develop circadian rhythms linked to light cycles. The bright light shouldn’t shine directly in babies’ eyes and they should be shielded from direct sunlight and wear sunscreen outside.
By four months of age, a baby’s sleep schedule should have become regular, more focused on nighttime sleep, and their blocks of sleep more “consolidated” or longer – especially at night.
The main thing, she says, is to make sure babies and small children get enough sleep on an increasingly regular schedule – and that their moms do too.
The period immediately after giving birth is a high-risk time for depression, even in women who have never had depression before. Those who have had depression, or have relatives who have suffered depression, are most at risk. This postpartum depression can be worsened by lack of sleep – or triggered by it.
“Chronic sleep deprivation is associated with an elevated risk for depression in everybody, at all stages of life, but in new moms, because of the hormonal changes and the need to recover from the pregnancy and birth, sleep deprivation can really be a problem,” Armitage concludes.
“It can interfere with the social rhythms that are important for keeping the circadian clock in the brain in sync, minimize the amount of energy moms have to care for their infants, and contribute to the development of depression.”