Letting babies cry for short periods of time while teaching them to sleep by themselves doesn’t cause long-term psychological problems or damage the parent-child relationship, says a study being published Monday in the journal Pediatrics.

The study, which followed children until they were 6 years old, will likely add fuel to an emotional debate that rages on playgrounds, on Facebook and within marriages: whether or not exhausted parents should “sleep train” their babies.

The behavioral techniques used in the study didn’t include the most controversial method, known as extinction, or “cry it out,” in which parents put the baby to bed, close the door and don’t open it until morning, no matter how long and vociferously the baby sobs. While effective, cry it out “is very distressing to parents,” said Anna Price, the lead author of the study and a postdoctoral research fellow at the Centre for Community Child Health, the Royal Children’s Hospital in Parkville, Australia. “It is hard to do. We don’t recommend it.”

Instead, the study used two somewhat gentler approaches. In “controlled comforting,” parents return to the room of a crying baby at regular intervals to offer some limited soothing. (Parents often refer to this as a version of cry it out.) It is the technique known colloquially as “Ferberizing,” after Richard Ferber, the doctor who popularized it. The method generally takes a few days to work, but some babies can need several “booster” rounds in later months.

In “camping out,” parents start by sitting in a chair next to the baby’s bed and slowly—over several weeks—move the chair until they are out of the room and the baby is falling asleep alone. Both techniques still usually involve some—sometimes a lot of—crying.

But some critics, including proponents of “attachment parenting”—which also advocates parents and baby sleeping in the same bed—assert that the Ferber method, too, weakens the bond between parent and child and can lead to behavioral and emotional problems later on.

On the other side, some advocates of sleep training have also said teaching children to go to sleep on their own is critical to helping prevent later sleep problems. But this study found no significant long-term benefits of the behavioral techniques. About 9% of children in both the intervention and the control group had sleep problems at age 6.

Earlier data from this study, and other research, have shown that the behavioral techniques do work and have clear short-term benefits: Babies go to sleep more quickly at bedtime and wake up less during the night. And infant sleep problems can lead to a whole host of family issues: They double the risk of depression symptoms in mothers and can fuel marital problems.”In the short term, the infants and parents get more sleep,” said Judith A. Owens, the director of sleep medicine at Children’s National Medical Center in Washington, D.C. “A well-rested parent is going to be a better parent in the daytime.”

The study followed 326 Australian children whose parents reported sleep problems when they were 7 months old. When the babies were between 8 and 10 months old, the parents of 173 children were taught the behavioral techniques during their regularly scheduled checkups. (Parents could choose which of the techniques to use.) The rest weren’t offered the training.

When the children were 6 years old, researchers administered various tests to assess emotional health, behavior, sleep issues and the quality of the parent-child relationship. Mothers were also screened for depression and anxiety. (The study controlled for factors such as socioeconomic status and child temperament.) Two saliva samples were taken to test children’s levels of cortisol, a stress hormone. Abnormal cortisol patterns can indicate that there was early exposure to high levels of stress, Dr. Price said.

Researchers found almost no difference on any of the measures between the children who had the sleep training as infants and those who didn’t. Interestingly, 16.5% of children in the control group scored as having emotional or behavioral problems, compared with 12.3% in the intervention group.

The study did lose a significant chunk of participants: About 30% of families whose children began the study as infants didn’t complete it.

Write to Andrea Petersen at andrea.petersen@wsj.com

A version of this article appeared September 10, 2012, on page A6 in the U.S. edition of The Wall Street Journal, with the headline: Letting Babies Cry a Bit Is OK.