Yes. Multiple studies have shown that sleep training is both safe and effective, without any studies showing evidence of harm. The best long-term study followed 326 children for the first six years of life. The authors reported that children who had sleep trained via any method in infancy slept better at 2 years of age than children who were not sleep trained, and their mothers were less likely to be depressed. Several years later, the researchers looked at these children again and noted that there was no evidence of emotional or behavioral problems in children who had been sleep trained versus those who had not. As part of this follow-up, the researchers measured the children’s levels of the stress hormone cortisol, which is frequently cited by opponents of sleep training as the mechanism by which crying affects developing brains. The researchers did not find any evidence of differing levels of cortisol secretion between children who had been sleep trained and those who had not.
Exhausted parents may be eager to get training underway—so how do you know when to start sleep training? “Most infants are ready for some sort of sleep training at 4 to 6 months,” says Lauren Kupersmith, MD, a clinical instructor at the department of pediatrics at NYU Langone Medical Center. “While some pediatricians adhere to the guidelines that infants are ready to be sleep trained when they achieve a particular weight, I feel it’s much more appropriate to wait until they are developmentally ready to self-soothe, at about 4 months old.”
While researching the different sleep training methods to decide which one is right for you, also remember that every baby and every family is different. What one mom swears by, another mom swears off. You will see the most success from sleep training if you use your intuition to pick a method that you know you and your baby will be comfortable with.
Finding the ideal bedtime can be tricky in the first few months of life. Infants who take a late afternoon nap (say, 4 to 6 p.m.) may go to bed as late as 9 or 10 p.m. A good rule of thumb is that your baby will probably sleep three to four hours after his last nap ends, but you may need to experiment, adjusting your baby’s nap and bedtime schedule to figure out what works best.
Pantley offers a gentle and gradual approach to all aspects of sleep, customized to your baby's needs. She recommends rocking and feeding your baby to the point of drowsiness before putting him down – and responding immediately if he cries. Parents are urged to keep sleep logs, nap logs, and night-waking logs. Pantley also describes a six-phase process for teaching a child to sleep in a crib.
Camping out involves gradually withdrawing your presence from your child’s room over the course of a week or two. This method is a good fit for parents who are not comfortable with prolonged crying, although it is important to recognize that, for some children, there is no such thing as a “no-cry” solution. The downside is that camping out takes longer than C.I.O.
It’s difficult if not impossible to sleep train if you share a bed with your child. There’s good evidence that bed sharing is associated with sleep difficulties in infancy and beyond. One survey of more than 50,000 Norwegian families showed that bed sharing was associated with more frequent night awakenings at both 6 and 18 months. Switching your child to sleeping independently for a week or so prior to sleep training can be helpful as you can soothe your child to sleep in the new sleeping environment first.
If your baby is older than six months, don’t worry, McGinn says: “It’s never too late to develop good sleep habits.” Dickinson says he finds nine months to be a bit of a sweet spot for parents in terms of getting babies to sleep through the night. “They are at a good age for understanding routines and don’t need to eat during the night,” he explains.