Last Updated May 22, 2019.

A lot of anti-sleep trainers out there talk in depth about cortisol in relation to crying babies. The basic idea is that crying is stressful for babies, so their brains will flood their bodies with cortisol – the stress hormone – which causes long-term damage to the brain itself, plus a number of other issues. Is this true? Are crying and cortisol detrimental to my baby’s health? And if yes, does that mean sleep training isn’t safe for my baby? Read on to learn the truth.

crying and cortisol

Photo Credit: Shelbey Miller

Dr. Schore

When I was a first time mother, this cortisol thing scared the crap out of me. Forget sleep training – I was terrified that my baby was getting flooded with cortisol all the other times she cried during the day, and that was a lot!

An article on states the following, “Dr. Allan Schore is often cited as showing that stress hormones like cortisol, released during intense crying, damage nerve cells in the brain, leading to unhealthy attachments and psychological disorders. He demonstrates that a repeated pattern of unmet needs disrupts a child’s stress-regulating systems and can alter the way her limbic structures process emotion.”

Petrifying, right?

This Schore dude is telling me that if my baby is crying intensely, their little body will release cortisol, and then they could have brain damage.  BRAIN DAMAGE.


Now, I’m not a doctor, but I’ve known lots of babies, and especially lots of babies that cry a lot. I don’t think I know any that have suffered brain damage. So, I dug a little deeper into this study that those anti-cry-it-out folks like to tout as the reason you shouldn’t use crying as a tool *ever* to help your baby or toddler learn to sleep. It turns out that, “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).” Source

So the study people use to tell me that I’m damaging my kids by letting them cry is based on data pulled from CPS.


New York Magazine

Can we take a step back now and talk about what sleep deprivation does to infants, toddlers, and kids? An article in New York magazine notes that, “The surprise is how much sleep affects academic performance and emotional stability, as well as phenomena that we assumed to be entirely unrelated, such as the international obesity epidemic and the rise of Attention Deficit Hyperactivity Disorder. A few scientists theorize that sleep problems during formative years can cause permanent changes in a child’s brain structure: damage that one can’t sleep off like a hangover. It’s even possible that many of the hallmark characteristics of being a tweener and teen—moodiness, depression, and even binge eating—are actually symptoms of chronic sleep deprivation.” (Emphasis added.) Source.

So here we have one scientist that’s taking data from abused kids and saying that in their cases, excessive crying (probably among other things), causes this cortisol release. And then we have a WHOLE BUNCH OF OTHER scientists telling us that lack of sleep amongst kids can cause symptoms of ADHD, obesity, and (also terrifyingly) permanent changes in brain structure.

If you’re on the fence about whether you think using crying as a tool to help your infant, toddler, or child learn to sleep is detrimental, shift your focus to what we know happens to the body and the brain when children don’t get the sleep they need.

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