Wednesday, October 17, 2012

What the Recent Research on "Cry it Out" Doesn't Tell Us

A few weeks ago, the news was full of stories about a long-term follow-up study that was used to see if a sleep intervention, started when infants were about 8 months old, had long term-effects (positive or negative) on babies, moms, or their relationship with each other. The authors' conclusion was a simple one; there was no long term effect on any of their measures. Hardly earth shattering stuff. But in this case, the lack of an effect was big news. In the original study (published in 2007), the authors reported that mothers in the intervention group reported fewer infant sleep problems and had better scores on a common depression scale (used at 10 and 12 months postpartum). Given that their study found no evidence of harm to the child 5 years later, the authors and the press concluded that "cry it out" methods of sleep training were safe and beneficial for parents who want to use them to get more sleep.

Our loyal readers already understand our bias. We don't like sleep training and we have certainly heard from those of you who do! Ok, so you're thinking who is right here? Which point of view does this research support? Unfortunately, neither. In this post, we'll take a closer look at this work and discuss what it does and doesn't tell us.

The Original Intervention

Maternal child health nurses in Melbourne, Australia were trained by the authors to provide sleep management support for mothers who reported sleep problems in their 7-month-old infants. Mothers were randomized (based on which clinic they attended) when their babies were 8-months-old into an intervention group that received the sleep management support or a control group that received standard care. The sleep management support included an assessment of the mothers concerns and an individualized sleep plan (education, handouts, and a choice of behavioral methods including "controlled crying" or "camping out"). Using "controlled crying" meant that babies were put in their cribs and allowed to cry until they fell asleep but parents were encouraged to go in periodically and console their babies, gradually increasing the intervals in between visits. Using "camping out," meant that the parents sat with the baby until the baby fell asleep but gradually reduced the time in the room over 3 weeks. Of the 174 families in the intervention group, 60 or about 34% chose to use one of these "cry it out" methods. At 10 and 12 months, the mothers were asked to answer a questionnaire about their babies' sleep and to fill out a screening tool used to identify depression.

Moms in the intervention group were less likely than moms in the control group to report that their babies had sleep problems at 10 and 12 months and they had better scores on the depression screening questionnaire (meaning they were at lower risk for depression). Follow up studies at two years showed that those depression scores were still better in the intervention moms even though there were no longer differences in the perception of sleep problems in their toddlers. After 5 years, the authors found no effect (good or bad) of the intervention on any measure.

What Have We Learned?

Reporters picking up on the story reported that this research proved that cry-it-out methods were effective and safe for babies (because they had no effect 5 years later).  And many parents who had used one of these methods (and people who make their living sleep-training) were deeply relieved. But there is another perspective...while the cry-it-out methods were part of this intervention, the researchers were really testing the benefits of health nurses offering invidualized sleep plans for parents who perceived their 8-month-old babies were having sleep problems. Only about a third of the families used the cry-it-out methods but 93% of the moms reported that it was very helpful to have someone to talk to about their concerns. Because of the study design, the real finding is that health nurses' support was safe and beneficial to the families, at least in the short term. By the time the children were 5-years-old, there was no difference between groups. We need to keep in mind that the families had other options to choose from for their indidualized plans (including using routines) and they received education on what could be expected as normal. Because the authors used the mothers' perceptions of sleep problems rather than objective measures of infant sleep, the explanation of what was normal could have in itself influenced this measure and reduced the mothers' stress. These were important features of the intervention that didn't show up in the news.

So what does all this mean? In our view, this study confirms that families need support throughout the first year (and beyond) in dealing with the stressful parts of their babies' behavior. Importantly, it also shows that moms who are not supported may be more at more risk for depression. But, this study does not provide evidence one way or the other specifically about cry-it-out methods since there was no randomization of those methods to one group or the other. We know that this is a passionate issue for a lot of families. Whatever your feelings about sleep training, we hope that we've helped you better understand what this recent work does and does not teach us.


Hiscock H, Bayer J, et al. Improving infant sleep and maternal mental health: a cluster randomised trial. Arch Dis Child 2007; 92: 952-958.

Hiscock H, Bayer JK, et al. Long-term mother and child mental health effects of a population-based infant sleep intervention: cluster-randomized, controlled trial. Pediatrics 2008; 122: e621.

Price AMH, Wake M, et al. Five-year follow-up of harms and benefits of behavioral infant sleep intervention: randomized trial. Pediatrics 2012; 130: 643-651.

Wake M, Price A, et al. Does an intervention that improves infant sleep also improve overweight at age 6? Follow-up of a randomised trial. Arch Dis Child 2011; 96: 526-532.


  1. What is this talk of "sleep training" anyway? It seems silly on its face if you understand that infants have different sleep cycles than adults, and that gradually those sleep cycles will change around to something more like the adult pattern. You can't "teach" that. You have to let them grow into it.

    Babies "learning to sleep" by being left to scream their heads off are going quiet because they've given up. Not the same thing as "learning to sleep." And them being OK five years later is subjective. So many people are emotionally messed up in this culture as children and adults--how can you *tell* they're "okay"?

    People need to learn more patience with small children, period. And yes, I'm a mother, but thanks for asking. I did have moments where I had to put my daughter down and walk out of the room. But I also suspect she had a physical problem that caused a lot of her evening crying--and eventually it was dealt with. (Her doctor told me he hardly ever saw a child feel the symptoms of the condition she had. I thought, "Well, you just met another one." As soon as they began treatment, her colicky symptoms disappeared.)

    And don't worry--my "indulging" her did not damage her ability to sleep whatsoever!

  2. Well... from my point of view, this new research suggests that CIO won't improve your parenting experience.

  3. This study did not really show effect of CIO as this article points out. We still don't know what methods were used in both groups actually because there was no data on it. The study actually measured the effect of support and the fact that a mom needed someone to talk to. Someone that would assure her, that there is nothing wrong with her baby. If parents, or let's just say moms adjust their expectations about their baby's sleep of course there will be less cases of maternal depression. I was there...I know...