WEDNESDAY, May 6, 2009 (HealthDay News) -- Women battling depression when their children are born are more likely to have infants with significant sleep issues and who run a higher risk of having early-onset depression during childhood, a new study says.
In the first six months of life, babies born to depressed mothers took longer to fall asleep at night, slept in shorter bursts and less soundly than infants born to mothers not experiencing depression. These high-risk infants also had more frequent but much shorter periods of sleep during the day, according to the findings published in the May 1 issue of Sleep.
Though unsure of the cause of these disruptive sleep patterns, the researchers said they believe the condition and its consequences could be reversed in the child.
"We do think that we could develop a behavioral and environmental intervention to improve entrainment of sleep and circadian rhythms in the high-risk infants," study lead author Roseanne Armitage, director of the Sleep and Chronophysiology Laboratory at the University of Michigan Depression Center, said in an American Academy of Sleep Medicine news release. "They may still be modifiable, since brain regulation is very plastic and responsive in childhood."
Past studies suggest that cortisol, a stress hormone produced in greater amounts by depressed women during pregnancy and after delivery, may affect the infant's ability to sleep.
If infant sleep problems are not addressed, they can become long-term issues that can affect not only the child's mental and physical health, but also the mother's, past studies have shown. This is a particular issue among people with maternal depression. The mother's health could further deteriorate if her child's sleep issues also cause her to lose valuable rest time.
Over six months starting at two weeks following birth, the researchers monitored the sleep of 18 full-term born children and their mothers for periods of seven consecutive days once a month. The mothers -- some of whom had no personal or family history of depression and others who had been diagnosed with depression or elevated depression symptoms -- also kept journals about daily sleeping and waking patterns.
The researchers said they think future studies should examine whether infant sleep patterns can be modified and what are the best conditions for nighttime sleep.
The New York University Child Study Center has more about childhood depression.