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.

No one likes to talk about sudden infant death syndrome (SIDS); it is a terrifying topic. SIDS is defined as the sudden death of an infant, which remains unexplained after a thorough investigation. These deaths occur in the first year of life, with the highest risk occurring between 2 and 6 months of age. Fortunately, these deaths are becoming less common, thanks in large part to the early ’90s Back to Sleep campaign, which urged parents to place infants to sleep on their backs. Suffocation is also a major risk for infants if they do not sleep in a safe sleeping environment.
But when he was about three-and-a-half months old, the routine fell apart. “I would feed him, but he wouldn’t be asleep at the end of the feed,” recalls Welk. “I would rock him until he fell asleep and put him down, and then he would wake up 30 minutes later and I would do it all over again.” Desperate for some rest, Welk brought Greyson into bed with her, but then she ended up just lying still, holding a pacifier in his mouth all night long. “I didn’t know anything about sleep,” says Welk. “I didn’t know you couldn’t just rock them to sleep and then put them down.”