Mothers who experience depression before or during pregnancy are more likely to have babies who have chaotic sleep patterns in the first six months of life. Professor Roseanne Armitage, of the University of Michigan Sleep and Chronophysiology Laboratory, states that not only does this add to parents' sleepless nights, but it may also set children up for their own depression in later life. Results are to be presented to the European Sleep Research Society meeting in Glasgow, Scotland.
New mothers are especially prone to depression because of a combination of hormonal changes, sleep deprivation and recovery from pregnancy.
Babies born to depressed mothers tend to sleep more during the day, wake up more often in the night, and take longer to settle down. "Going to bed at the same time, getting up ant the same time, establishing rituals aroundthe bedtime helps infants to distinguish between night and day sleep," Armitage says. "Put the baby in day clothes for naps, and in night clothes for night sleep - babies pick up these cues."
Evidence to date points to a relationship between depression, light-dark exposure, circadian rhythms and sleep. Armitage and colleagues were interested to see whether such relationships might extend to infants. The research team compared results obtained from mothers who had sought help for depression with those who were free from depression prior to and during pregnancy. They found distinct differences in the sleep patterns of babies from depressed mothers.
Volunteer mothers were asked to wear wrist actigraphs, which record sleep time, light exposure, activity and rest patterns. Actigraphs were worn during the last trimester of pregnancy. Two weeks after babies were born, each baby was fitted with a tiny wrist actigraph for a period of eight months.
Analysis of data showed that babies born to non-depressed mothers have an in-born 24 circadian rhythm soon after they are born. This was not the case with babies born to depressed mothers who showed little or no evidence of an in-born body clock. "We think we've identified one of the risk factors that may contribute to these infants' going on to develop depression in later life," Armitage said, "if sleep is consistently disrupted and circadian rhythms are weak, the risk is significantly elevated."
Professor Armitage views the first few months of a baby's life as a training period for the future sleep behavior. By four months of age a sleep pattern should have been established where sleep is more focused on nights than days.
Published On: September 09, 2008