We’ve all seen the warnings that sleep training causes so much stress to a baby that cortisol floods the brain, killing neurons and altering development.
Even without these alarming stories, most parents considering sleep training naturally worry about how stressful it is to a baby. None of us like to hear our babies cry. It makes us feel stressed, and the baby probably feels the same way. But how stressful is it? And is it damaging to a baby’s brain?
Despite decades of research on sleep training, most studies have focused on outcomes related to sleep and daytime behavior, but few have examined babies’ stress responses to this change. Those that warn that letting babies cry is damaging to their brains cite studies of babies that were subjected to chronic neglect or abuse or raised in orphanages and lacking strong attachment figures. These are examples of chronic, toxic stress. They are deeply saddening to me, but I’m not convinced that they tell me, or any other loving parent, much about the effects of sleep training my little girl.
This has left me digging through reams of research, trying to put sleep training in perspective among other sources of infant stress. A good place to start is the American Academy of Pediatrics’ (AAP) recently released report entitled The Lifelong Effects of Early Childhood Adversity and Toxic Stress  and an accompanying policy statement. The AAP report gives us a framework for looking at stress that I think is very useful. It defines 3 types of stress responses in children: Read more