Difficult Baby BannerIt was to my utter dismay to be led to yet another article touting the benefits of crying-it-out (CIO) and admonishing those who speak out against it.  However, it was even more distressing to read an article that so blatantly attacked researchers and held up research that has been openly criticized as “bad science” as evidence supporting CIO.  But I’m jumping ahead.  Let me regress…

In an article on Slate, one author grabbed headlines with a statement that an entire journal “jump

[ed] on the Dr. Sears bandwagon” by publishing an issue dedicated to infant sleep and the questions and concerns that exist surrounding CIO.  In fact, the entire tagline reads “A journal jumps on the Dr. Sears bandwagon to say sleep training is dangerous.  Science says otherwise.”  Let’s first get something clear – journals publish special issues all the time and journals publish research and opinion pieces and reviews from researchers who work in the relevant fields.  They don’t go to a local coffee shop and ask Joe-Shmoe what he thinks about CIO.  They ask for pieces from professionals.  Those in science if you will.  And their conclusion here was that sleep training is dangerous.

Second, many of these researchers have been doing work long before Dr. Sears and his attachment parenting took hold.  To suggest they’ve jumped on a bandwagon is utterly insulting to the entire field of science.  It’s something Fox News would pull out and reminds me of accusations of researchers jumping on the climate change bandwagon.  No – scientists form their opinions based on the research they read and conduct.  Do they all fall in line and form the same opinion?  No.  Because science isn’t absolute and perfect – it has flaws.  But to suggest one camp is following a bandwagon while the other (one that fits with what you believe) is actual science is absurd.

Now, with that idiocy out of the way, let’s get to the meat of the article.  The author accuses the journal of making overstatements about the research that speaks out against CIO and of ignoring the research that says it’s safe.  I won’t speak much about the accusation of overstatements.  You can read any of the following pieces to see where I stand and what most of this research is speaking to (though her examples, with the exception of one, are not ones I’ve included herein):


If you read these, you can hopefully see that there is evidence suggesting that CIO may be harmful to children or at least sends your children a message you may not wish to send.  Will you forever damage your child?  No.  Might you inadvertently harm them somewhat?  Yes, and some of this may have a lot to do with your child’s temperament, something that none of the research takes into account.  However, it’s a bigger topic for another day.  Here, I’d like to speak more to this idea that “Science says otherwise” that permeates the article and hopefully make clear that this statement is an overstatement at best, a lie at worst (sound familiar?).  The first bit of science she refers to is that attachment isn’t based on the list of things Sears offers.  I agree and this is the one point that I hope people can take home from the article.  But then she says:

But what if it takes weeks of intense crying, night after night, to sleep train your child? Here’s the thing: When crying-it-out is done properly, the experts say, it doesn’t take weeks. It takes days…

I asked Marc Weissbluth, a pediatrician at Northwestern University and the author of the best-selling Healthy Sleep Habits, Happy Child, about the discrepancy, and he says that crying-it-out can take a long time, but typically only if the parents “have the child’s bedtime too late, or they’re not napping the child, or they’re doing intermittent reinforcement,”—i.e. they’re going back in to soothe the child instead of truly letting them cry it out. (Extremely overtired babies resist sleep training, and parents who soothe their babies during training reward the crying, giving them reason to do it again and again.) Fix these problems, Weissbluth says, and crying-it-out should work in three days.

Okay, so point one is that you shouldn’t respond to your child at all.  Based on Dr. Weissbluth’s answer, we are clearly in behaviourist territory.  The same theories that gave us the idea that we shouldn’t touch our children too much for fear of spoiling them and that the only lessons children and infants learn is to do with behaviour.  It also ignores all the families with children with reflux or food intolerances who scream night after night in pain.  Personally, whenever I see someone hop on the Watson bandwagon (note: John Watson was the key proponent of behaviourism with infants), I shake my head and dismiss.  Why?  Because even Watson admitted he was wrong when it came to children and child-rearing in his application of behaviourist theory.

Next she brings up the review in the journal Sleep[2], which found success for CIO in 17 of 19 studies that only looked at CIO (and not controlled crying, or Ferberization) and “none of the studies found side effects associated with sleep training”.  We will get to the idea of “success” in a moment, but I will simply repeat here was I have written elsewhere on this particular review (and one other because the two are linked in terms of the studies reviewed) and the idea that there were no side effects associated with sleep training…

Before I get into the evidence against CIO, I have to address the elephant in the room, which is that two reviews have been cited by sleep stores and trainers galore demonstrating no ill effects of sleep training.  The first, in Sleep Medicine Reviews, simply states “no evidence of deleterious effects was found in these studies”[3] (p.284).  So how many studies were cited as showing no deleterious effects?  Three.  And one of them is a case study of FOUR children – not really a study at all.  So two studies and one case study.  But what if two studies found no deleterious effects – that counts right?  You bet, if they actually used valid measures of child attachment or social-emotional health, but of course they didn’t.  Both studies[4][5] utilized parent-report measures of “attachment”, in quotes because one of them ([4]) utilized a scale that doesn’t even claim to measure attachment, but rather parental stress while other ([5]) modified a measure that is supposed to be administered by a trained interviewer (in order to be objective and delve deeper when necessary) into a self-report measure, in essence invalidating the measure.  Furthermore, neither study included long-term assessments of behaviour, only pre- and post-sleep training.  Finally, the youngest child in these studies was 16 months of age, a far cry from the 4 months that many parents are encouraged to start sleep training.

The second review, and probably more commonly cited, was in the journal Sleep[3] and included 52 studies while claiming to find no secondary effects for sleep training.  The first problem here is that not all 52 studies actually examined side effects so it’s not like 52 studies didn’t find deleterious effects, only the ones that did study it found no deleterious effects.  What are these potentially deleterious secondary effects examined?  They are: attachment status, predictability, irritability, and crying/fussiness.  Personally, the last three make no sense to me as secondary effects on the child’s well-being, but so be it.  However, the examination of attachment status is highly interesting, if it has a chance at being different from the previous review.  Again, though, only three articles were found that assessed attachment, not 52.  Unfortunately, they all suffered the same flaws as mentioned above (and one of them was the same study, [5], as cited above), including the use of the exact same self-report measure for attachment (that’s supposed to be administered by a trained professional).  Personally, I see none of this as providing much evidence of anything, except that sleep training helps parents.  And even if you accept the results of the reviews, no research that is based on children in the 16+ month range is at all applicable to children who are younger, which is when the vast majority of CIO techniques are used.

[From What You Need to Know About Crying-It-Out]

But what of “success”?  It sounds like these studies all found overwhelming success.  Except they didn’t.  Well, that’s not quite true, the studies did find success in terms of infant sleep (and nothing else) was maintained over 3 to 6 months.  Only most of them didn’t have a comparison group to see what children naturally did.  Luckily for us, the Infant Sleep Information Source, headed by Drs. Helen Ball and Charlotte Russell out of Durham University, have done this, and guess what they found?  Well, in their own words:

Although the vast majority of studies have reported initial increases in infant sleep duration, and/or reduction in night waking, relatively few studies have investigated whether this effect persists long-term. Of the studies that have addressed this issue (only 3 – one quarter of the publications we systematically reviewed for this summary) none found an effect lasting 6 months or more after the sleep training methods was originally used, and found to ‘improve’ babies sleep. This means that the initial improvement, or ‘benefit’ of using the method disappeared, and outcomes were the same for the group of babies who had been ‘sleep trained’ as for those in the control group who had not.

The next bit of “science” in support of CIO comes from the recently publicized work out of Australia claiming to be a long-term analysis of CIO.  I’ve written a piece highlighting the many methodological flaws of this study which was published as an eLetter on Pediatrics in response to this piece along with many other researchers who were concerned that research of such poor quality was published.  Not to mention published by people who run sleep clinics to train babies.  Conflict of interest much?  Anyhow, I did a full piece for EP as well on this article which you can read here (see A Not-So-Blind Review of the Recent CIO Research).  For those who wish to read a summary here is the bulk of the eLetter:

Arguably the most serious problem is the lack of control in the control group. Despite randomizing the groups, little to nothing is known about either what the parents in the control group actually did vis-a-vis sleep behaviour or what the nurses discussed with the control group families. Apparently the researchers assumed that these families did not take part in any sleep training with no evidence to support such an assumption (especially when myriad resources suggest sleep training as a remedy for infant sleep problems). As is, the control group is not a true control group with respect to sleep training outcomes.

The second concern pertains to the misuse of the intention-to-treat principle. Although there was an element of self-selecting in the experimental group, that self-selection would not have unfairly biased the outcomes being measured. If indeed there are long-term effects, they have ostensibly been masked by the inclusion of the nearly 43% of the experimental group who refused the experimental protocol (i.e., sleep training). A parallel would be examinations of breastfeeding outcomes. Researchers do not examine these outcomes based on what women intended to do (despite that being important in many ways) but rather what the actual behaviour was. In these instances it is better to collect data on the possible confounds and control for them statistically than to utilize the intention-to-treat principle. Currently, we have outcomes for those who did not sleep train included in the outcomes of those who did which only serves to muddy the waters.

The third concern is that the measures used to assess child outcomes are parent-report. What the authors have presented is an assessment of parental perception of child attachment and behaviour; there is no objective or child-report measure included (with the exception of child health). Parents’ perceptions may be colored by their choice (to take part in sleep training or not) and feelings of having intervened rather than the intervention itself and should be supplemented with other measures, especially as the researchers did do a home visit, making this type of assessment possible.

Overall it seems that the authors tried to make their data fit a pressing research question. Unfortunately, what has resulted is a study that has no bearing on the question of interest, and thus more research remains needed. Despite what the authors would like us to believe, we are no closer to knowing the long-term effects of sleep training than we were prior to the publication of this article.

Next the author turns to the ever-importance of sleep.  Now, no one argues that sleep isn’t important, but infant sleep is very different than adult sleep and we must be cognizant of the developmental stage infants and toddlers are in and respect their stage and their individual differences.  Often what parents believe is a problem for infants is in fact a problem for the adults, not the infants.  Studies looking at infant sleep found that parents didn’t think their children or infants showed signs of sleep deprivation at all, but that their child’s sleep was a problem for them (see here for a bigger discussion).

In an attempt to suggest sleep problems in infancy persist, the author cites a study by Zuckerman and colleagues[6] which found a certain level of continuity between night wakings at 8 months and at 3 years.  Specifically, 41% of children with a “problem” (really hard to call normal, age-appropriate behaviour a problem, but it was for the parents) at 8 months had a problem at 3 years whereas 26% of the children with no problem at 8 months had a problem at 3 years.

First, this statement ignores the most recent findings by Marsha Weinraub and colleagues who found that simple, normal development means a large portion of children will be waking regularly until 3 years of age[7].  (If you think this research supports CIO, as the popular media suggests, I recommend you read this, as it does not.)  So really at this stage we’re looking at normal, age-appropriate behaviour.  And outside of this study there is NONE that suggests night waking in infancy predicts sleep problems in later childhood.  Second, the numbers are somewhat disingenuous.  At 8 months 18% of mothers reported that either their 8 month olds woke 3 or more times per night (very normal, especially for breastfed babies), took an hour or more to settle after waking (more common in formula-fed babies), or their own sleep was disrupted by their infant’s sleep.  However, by 3 years of age 29% of children were reported as having problems.  So there is an increase in problems here.

I would believe that the infants who started with a “problem” and continued with one may be those who simply aren’t developmentally ready for consolidated sleep (and for whom we have not been able to show any long-term negative impact), I’m personally more concerned about the kids who didn’t have a problem and now do.  What happened?  But we don’t talk about that.  In short, this study offers us nothing in terms of long-term consequences except telling us that some children are on a normal trajectory and some aren’t.  Yet we’re more worried about those that are on the normal track.


Finally, the author pulls out the depression card, and this is where “success” comes back into the picture.  Yes, there is research that depression is a problem for babies and mothers.  There is even evidence that sleep training or CIO can help the mother.  Now, remember that most infant sleep problems are actually parent reported problems, not necessarily infant sleep problems.  So if a bit of extra sleep helps alleviate mom’s symptoms, that helps mom and reports of “success” exist.  As stated in the review by ISIS[8]:

Some studies found that the improvement seen in mothers’ or babies’ sleep was only significant for part of the group who took part. Hiscock & Wake, for example, conducted a large randomised trial of controlled-crying/camping out, with 8-10 months old babies. They found that the overall improvement seen in the number of mothers reporting infant sleep problems two months later was due to significant improvement occurring only in the sub-group of participants that included depressed mothers. There was no significant improvement in the ‘non-depressed’ group.

But as I’ve mentioned elsewhere, this is where we run into problems.  Why on earth would we put the onus of mom’s depression on a young infant?  Why do we not work to have better support systems and help in place so that mom doesn’t have to resort to sleep training?  It’s something I don’t think I’ll ever understand.

The author’s final paragraph is this:

Crying-it-out is not for every parent, I know. But desperate parents—or parents who just want to be done with the 2 a.m. wake up— should feel fine trying the method. It’s not just that there’s no evidence of harm in crying-it-out—there is some solid evidence of no harm. When sleep training works, and research suggests it often does, it can provide long-term benefits for the entire family—giving babies the sleep they need to develop into healthy toddlers and giving parents the rest they need to be sensitive, confident, and happy caregivers.

All I can say is that I hope by now you can see how disingenuous it is.  The author starts her piece by accusing the authors of the Clinical Lactation special issue of cherry picking research to support their position.  I think she needs to take a long, hard look in the mirror on that one.

[Image Credit: Unknown]


[1] Middlemiss W, Granger DA, Goldberg WA, Nathans L.  Asynchrony of mother-infant hypothalamic-pituitary-adrenal axis activity following extinction of infant crying responses induced during the transition to sleep.  Early Human Development 2012; 88: 227-32.

[2] Mindell JA, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A.  Behavioral treatment of bedtime problems and night wakings in infants and young children.  Sleep 2006; 29: 1263-1276.

[3] Owens JL, France KG, Wiggs L.  Behavioural and cognitive-behavioural interventions for sleep disorders in infants and children: a review.  Sleep Medicine Reviews 1999; 3: 281-302.

[4] Reid MJ, Walter AL, O’Leary SG.  Treatment of young children’s bedtime refusal and nighttime wakings: a comparison of “standard” and graduated ignoring procedures.  Journal of Abnormal Child Psychology 1999; 27: 5-16.

[5] France KG.  Behavior characteristics and security in sleep-disturbed infants treated with extinction.  Journal of Pediatric Psychology 1992; 17: 467-475.

[6] Zuckerman B, Stevenson J, Bailey V.  Sleep problems in early childhood: continuities, predictive factors, and behavioral correlates.  Pediatrics 1987; 80: 664-71.

[7] Weinraub M, Bender RH, Friedman SL, Susman EJ, Knoke B, Bradley R, Houts R, Williams J. Patterns of developmental change in infants’ nighttime sleep awakenings from 6 through 36 months of age.  Developmental Psychology 2012; 48: 1511-1528.

[8] http://www.isisonline.org.uk/how_babies_sleep/sleep_training/research_evidence/