Parents are often hesitant to go this route, worried about how much crying will be involved. While McGinn doesn’t deny it can be difficult at first, she finds parents are often surprised by how quickly it works. “Yes, there is a lot of crying, but it’s short term,” she says. “You might get a lot of crying for two to three nights, but then every night is less and less.” She says you should see significant improvement with this method by night three or four but adds that it’s important to try it for a week before determining that it’s not working.
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.
Most sleep coaches say the ideal time to start sleep training (or promote independent sleep, not necessarily using the cry-it-out method) is based on your baby’s development, but is usually somewhere between four and six months, when your baby hasn’t had much time to get used to nursing or rocking to sleep. At this stage, most babies are also developmentally ready to learn the skill of falling asleep on their own, explains Jennifer Garden, an occupational therapist who runs Sleepdreams in Vancouver. Around four months of age, some babies go through a sleep regression because their sleep cycles change and there are longer periods of lighter sleep per cycle. “It’s a great time to work on independent sleep skills,” says McGinn. Other babies’ slumber derails around this time because they are working on new skills, like moving around and rolling. Some parents choose to wait until things settle down before embarking on a sleep-training method, but you don’t have to, says McGinn.