What does research and science say about sleep training?
What do studies actually show when it comes to sleep training?
Sleep training is definitely a touchy one, the elephant in the room in the sleep training world, especially because so many don’t agree with it and find it wrong and controversial due to the crying aspect (among other things). And I get it, leaving your baby to cry seems cruel, unnatural, harsh, etc…and I get where the controversy comes from to begin with. But it's important to shed light on it so that we have clarity on what the outcomes really are and what research really says on the short and long term impacts of crying during sleep training.
There is so much literature out there with fear-mongering claims about the long term dangers of sleep training a baby using any form of crying (extinction, bedtime fading and even controlled crying). Thanks to the infamous Dr. Sears who misconstrued the research and instilled fear in generations of people claiming that sleep training and letting babies cry it out would flood their brain with adrenaline and cortisol causing all sorts of long term damage like chronic stress, social and emotional issues, psychological issues, etc…but I won’t get into too much detail about that now. I won’t get into too much detail about it here.
Below I’ve listed some popular claims that have been made about the dangers of sleep training.
Emotional/behavioral issues
Psychological damage
Hindered parent - child attachment
Chronic stress, etc…
Sifting through all this info can be quite a task, especially when it comes to knowing what’s true and what’s not. But that’s why we’re gonna turn to research and science, and not just any research, but research backed by the AAP, The National Institute of Health, The American Academy of Sleep Medicine and many many more.
What research does find is quite the opposite from what the things listed above. They’ve found that crying actually causes no short or long term trauma or damage to an infant, and this was based on research done on babies who underwent very traditional forms of sleep training. There have been many studies done on crying during sleep training and the results are interesting. You will be pleasantly surprised to hear that there are no adverse effects from crying.
They’ve found:
Fewer night wakings
Improved sleep for mom and baby
Less crying overall at bedtime and when put to sleep
Less sleep disturbances and issues.
Improved Maternal mental health and well-being.
And no difference in social and emotional behavior at the 5 year follow up compared t o babies who were not sleep trained.
So let’s and go ahead look at the actual research up close…
What research says:
In one study, The AAP published an article on research done by Australian researchers who followed up with 173 6-year-olds who had been sleep trained as babies, some of whom with graduated extinction, bedtime fading and babies who were not sleep trained at all. They found that they were no different than non-sleep-trained 6-year-olds with regards to emotional development, psychological health, parent-child closeness, and parental attachment. No impacts long term when measuring child’s behavior, emotional well being and the parent-child attachment. The behavioral and emotional scores 5 years following this trial were the same as babies who had not been sleep trained
Conclusion: "Behavioral sleep techniques have no marked long-lasting effects (positive or negative). Parents and health professionals can confidently use these techniques to reduce the short- to medium-term burden of infant sleep problems and maternal depression."
Here’s another article published by the AAP that evaluates the effects of sleep training and sleep patterns of infants. It also measures infant stress, and determines whether sleep interventions cause any emotional/behavioral problems for the child or affects the parent-child attachment.
Conclusion: "Both graduated extinction and bedtime fading provide significant sleep benefits above control, yet convey no adverse stress responses or long-term effects on parent-child attachment or child emotions and behavior."
The Association for Child and Adolescent Mental Health did a study on sleep training 178 infants who were assessed at different times from birth to 18 months, some were left to cry it out, some were not and there was increased crying by 18 months with infants who were not left to cry vs. a decrease in infant crying and fussiness by 18 months with babies who underwent sleep training.
Conclusion: "Parental use of 'cry it out' in infants: no adverse effects on attachment and behavioral development at 18 months."
An article in The Canadian Family Physician did a trial at different ages on infants who were sleep trained at around 7 months old using controlled crying vs. infants who received regular care (no sleep training). Statistical data showed a significant decrease in crying and fewer night wakings by 10 months old and a significant improvement in maternal health.
Conclusion: "Sleep training improves infant sleep problems, with about 1 in 4 to 1 in 10 benefiting compared with no sleep training, with no adverse effects reported after 5 years. Maternal mood scales also statistically significantly improved; patients with the lowest baseline depression scores benefited the most."
A journal, Slate.com, reviews the popular claim made by Dr.Sears on how sleep training is dangerous and harmful for an infant because it floods the brain with cortisol causing long term stress and psychological damage. And they reported that babies who are allowed to ‘cry it out’ were no more stressed than babies who had their parents respond to every cry.
Conclusion: "The American Academy of Sleep Medicine reviewed the literature on infant and child sleep training, it reported that in 17 out of 19 published studies, unmodified extinction—the clinical term for crying-it-out—effectively reduced bedtime resistance and the frequency of nighttime wakings, concluding that it “has a strong record of accomplishment.”
This Australian study was done to determine if sleep training would improve maternal mental health and they demonstrate that in this study.
Conclusion: "Implementing this sleep intervention may lead to health gains for infants and mothers..."
THE BOTTOM LINE:
Studies have shown that there was no difference in behavior in children who were sleep trained vs not sleep trained by age 6 -7. There was no difference in the parent child attachment vs. children who were not sleep trained. And the question of “will sleep training my baby cause brain damage or cause long term negative or permanent side effects?” can be put to rest. The claims of brain, personality, and attachment damage come from research conducted with grossly neglected children (some studies use data from Child Protective Services cases), not from children who undergo a few days of sleep training and who come from healthy homes.
And last but not least (cause there are endless things to write about this topic), The AAP has stated that parents and health professionals can confidently use sleep training techniques and interventions to reduce the infant sleep problems and maternal depression.
I hope this has shed some light and eased your mind a bit and that you can feel more at peace with the idea of sleep training.
