Is "cry it out" harmful or helpful?

A well-known sleep training method is called “cry it out” (CIO) for a reason—it typically involves the baby crying until she falls asleep. Because the crying may signify that the baby is experiencing stress, opponents of the method consider it harsh and potentially damaging. Research suggests that excessive stress-induced crying may be linked to brain changes during a critical growth period. Critics of the method also argue that babies learn that they cannot trust their environment and caregivers, since their crying is unanswered. 

It’s hard to evaluate the long-term effects of CIO—or any other sleep training technique—because there are a host of other factors that influence infant and child development, both physically and psychologically. 

Mounting research suggests that some forms of sleep training work well and are not linked to negative effects. For example, modified CIO approaches – such as gradually delaying responding to an infant’s cries, or “bedtime fading” which involves delaying the infant’s bedtime by 15 minutes each night to compress the child’s sleep into one block – seem to be viable alternatives for many families. There is limited evidence that these and other techniques like staying in the room with a baby until she falls asleep, or briefly responding to a baby’s cries without extended cuddling, lead to more emotional and behavioral problems, or worse parent-child attachment.   

Not sleeping through the night is normal for newborns & babies

Not sleeping through the night is biologically normal for the first year or two, and frequent awakenings may help to protect against sudden infant death syndrome (SIDS). Typically, older babies awaken less often during the night than newborns do, but this can vary according to developmental stage. For example, at 6 to 9 months of age, many babies are so excited by their growing abilities (sitting, crawling, and so on) that sleep can be a challenge. 

Generally, any method of sleep training should not be considered before 6 months of age. The stomachs of newborn infants are very small, so it’s simply not possible to meet your newborn’s caloric needs without some nighttime feedings. Eventually, babies will learn to sleep through the night, but when this happens is different for every baby.

While at times it may feel like your child is never going to sleep through the night, take heart! Good sleep behaviors will come, with time and patience, and a consistent, age-appropriate bedtime routine.

Learn more about sleep training tips here.  

Last updated August 17, 2020

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