Crying and waking up in the middle of night are routine during any newborn’s first few months. But if those wailing episodes continue on a regular basis past the first year, then they may signal possible behavioral problems down the road.
That’s what researchers in Europe found when they analyzed nearly two dozen studies on something developmental experts call regulatory problems — which include trouble sleeping, continuous crying and difficulty feeding. The researchers report in the journal Archives of Disease in Childhood that infants who consistently cry and wake up at night past their third month are nearly twice as likely to develop problems such as attention deficit hyperactivity disorder (ADHD), depression, anxiety, aggressive behavior or conduct disorders by the time they begin school.
The most common behavioral difficulties these children had involved lack of self-control, and an inability to calm themselves down or act appropriately in different social situations. “We found a particularly strong relationship between regulatory problems in infancy and conduct disorders or ADHD, which are problems of under-control, in which children can’t regulate their attention, or fly off the handle and can’t control their behavior,” says Dieter Wolke, one of the study co-authors and a professor of developmental psychology at University of Warwick in England.
How exactly are extended crying jags and picky eating during infancy related to later behavioral problems? Wolke says the data don’t support any obvious link, but there are several possibilities. One, the crying and waking up at night are simply the first signs of a behavioral problems involving lack of self-control. Every baby wakes up several times a night and may start crying, but most will eventually learn to calm themselves down and settle back to sleep. They learn that enough is enough and inevitably figure out that Mom and Dad won’t come running every time they wail. If babies are already prone to developing a behavioral disorder, however, they may not be able to learn such self-control, and their crying episodes may continue well past their first year.
In addition, says Wolke, some infants may be genetically susceptible to problems regulating their behavior; specifically, scientists have recently identified a version of a gene involved in dopamine function, which governs mood and emotions as well as motor function, that may make some infants more vulnerable to behavioral problems.
Alternatively, the babies — and their parents — may perpetuate their own behavioral difficulties, since their continuous problems sleeping and feeding may force their parents to do something about them, rather than leave their newborns to cry miserably. Instead of allowing their babies to teach themselves to settle back to sleep when they wake at night, for example, parents may instead come in and rock them or feed them or distract them in some other way; these infants would then only find it harder to learn to control their behavior or emotions — including aggression or anger — as they get older.
The results, while sobering, don’t imply that every child who has crying fits, wakes up repeatedly at night or is a fussy eater, will grow up to have behavior problems. About 20% of infants have such regulatory problems, says Wolke, and these are defined as extending beyond the usual three months that most newborns take to settle into a regular feeding and sleeping routine. And it’s not so much the frequency of the crying, says Wolke, but the fact that the infant won’t — or can’t — stop.
But even if your baby falls into that 20%, it doesn’t necessarily mean he or she will become a problem child later. The current study suggests that if parents recognize these symptoms of regulatory problems early on, they may be able to parent in ways that will help their infants learn more self-control — before the problem becomes more ingrained and difficult to change.
Instead of running in to pick up their baby each time he cries, for example, parents can learn to establish a bedtime routine that will ease their newborns transition to sleep and allow them to sleep more soundly. Leaving the baby alone before he falls asleep might also help, as that would encourage the him to find ways to doze off on his own.
Wolke is the first to admit that additional studies will need to be done in order to prove that such interventions can affect the development of behavioral disorders in childhood, but, he says, “because of the link we found, if these babies learn early on to control their behavior, like learning to stop crying or falling asleep on their own, then we could have a massive public health impact in preventing other behavior problems in childhood.”
If true, it would certainly help thousands of parents and their children — not just to get a good night’s sleep in the child’s first few months, but perhaps throughout their young lives as well.