The project worked with 43 families and found that leaving infants to cry at bedtime, using a timed technique, improved sleep patterns and had no apparent downside.
The psychologists at Flinders University in South Australia, observed that following training the babies took less time to fall asleep and were less likely to wake in the night.
Lead researcher Michael Gradisar, said it was natural for parents to worry and to want to comfort their crying babies at bedtime, but added that the results showed it could be better to resist.
‘We ran the numbers and found that those children who experienced delayed sleep or were allowed to cry longer ended up falling asleep faster,’ said Associate Professor Gradisar.
‘They were not waking up so much in the night either.
‘The significant finding in this study was there were no elevated cortisol readings in the infants.
‘They stayed within normal limits.
‘Not only did we measure cortisol, but 12 months after the intervention, also child-parent attachment, and children's emotions and behaviours.’
He added that the findings were similar to those of another Australian study of more than 300 families.
Five years after the interventions there were no behavioural or emotional issues, neither with the children, nor significant issues with the parent-child relationship.
Previously, opposing claims have been made that while the ‘Ferber Method’ can bring some benefits for both babies and parents, the pros were temporary and cancelled out by problems later on.
These include stress, sleep problems and separation issues.
Prof Gradisar published an article in 2012 (Download here) suggesting that a widely reported University of North Texas study had caused unnecessary alarm.
His research included a randomised controlled trial that involved 43 infants past six months of age who displayed night-time sleep issues.
The infants were split into three groups to which the two different techniques were applied, and a control group involving no intervention. Their saliva was tested for cortisol.
In both the ‘graduated extinction group’, where babies were initially allowed to cry for varied increments of time, and a 'bedtime fading group' where the bedtime was extended, there were no increases in chronic stress levels during the 12 months.
Infant attachment to their parents was also recorded on video and parents were asked to report on their child’s emotions and behaviours.
‘Initially all children were taking 20 minutes to fall asleep but after one week the children in the graduated extinction group and the bedtime fading group were falling asleep between five to ten minutes and maintained that throughout the year,’ said Assoc Prof Gradisar.
‘The control group still took 20 minutes to fall asleep.
‘Obviously there still needs to be more research but we would encourage parents to try the bedtime fading technique because it’s definitely a gentler method.'
The study, called ‘Behavioural Interventions for Infant Sleep Problems: A Randomized Controlled Trial’, will be published next month in the American Pediatrics journal.