How Effective is Controlled Crying? (Hint: Not Very)

Cry-it-out (CIO) and the supposedly more “gentle” controlled crying (CC) are highly touted methods of dealing with the “problem” of infant night waking.  The entire premise ignores that infant night wakings are not actually a problem for the infant and indeed may even be adaptive (see here for a discussion), but they have gained massive popularity in Western societies where the idea of any sleep deprivation is seen as untenable by many parents.

Although the few control trials that have looked at longer-term efficacy of sleep training have found no difference in sleep quality for parents (see

[1] for a review), people continue to believe that it will be the saviour that helps them cope with the sleepless nights that inevitably accompany the appearance of a newborn.  Why shouldn’t they?  As most studies on the topic are not controlled, there are ample non-controlled studies out there telling parents that CC is successful (for a review, see [2]), but the question we have to ask is, is it successful?  What about when we take parents out of a clinical or research setting and put them back in at home?

In one highly-publicized long-term study out of Australia that tried to claim no difference in long-term outcomes from CC or not[3] (which really claimed nothing of the sort given the data and analyses conducted, see here for a discussion), they acknowledged that 42.5% of the families who were allocated to the sleep training group refused participation yet were included in analyses as if they had completed it.  In the earlier report on the efficacy of sleep training in the same group, of those who agreed to hear out the intervention or try it (along with discussions of how infants need to be “taught” to self-settle and that if they don’t it’s due to behaviours by the parent that can be modified, via CC), just over 30% said it didn’t work[4].

Notably, although the authors report that their intervention was more successful at helping infant sleep compared to a control group that only received normative sleep information, this only held for those who scored high on depression.  This may be explained by the use of a technique that allows the parent to be proactive (a common technique when treated depression via a cognitive-behavioural therapy model).  This data is important because contrary to other studies that were solely in a clinical or research setting, this relied upon parent information from the home use of CC.  As such, we need to ask: If we’re going to push methods that we don’t have complete data on with respect to infant outcomes, shouldn’t we at least know how well they work for the parents they’re supposed to help?  So far, no one has bothered to answer that question.

 

Enter Lynn Loutzenhiser and colleagues in Canada who decided to look how successful CC was for parents who implemented the well-known technique at home[5].  Dr. Loutzenhiser and colleagues start by discussing the various reasons why we might even hypothesize that CC is less likely to be successful at home, which include the lack of support for parents (because let’s face it, not responding to your crying infant is denying, for most people, an instinctual response), the fact that many parents start prior to six months which is not suggested by most researchers or doctors (to top it off, a recent systematic review found that any form of sleep training prior to six months – including things like eat, play, sleep – not only didn’t work but increased the risk of negative outcomes[6]), or that no one knows how long it takes (despite popular opinion that it’s just “a couple nights of crying”).

The study?  Well, it starts with 411 Canadian parents of 6-12-month-old infants (for the reasons stated above, looking earlier than six months would be unethical).  The Canadian bit is notable because we (yes, we, I’m Canadian) have a year’s paid parental leave available to us which means the likelihood that parents are home and able to rest with their children is far higher than might be expected in the United States where parents are expected back at work at 6-12 weeks.  All but six of the parents were mothers, nearly 93% were Caucasian, nearly 97% were married, and the SES level was rather high.  In short, this was not a “typical” sample, but may be typical of the type of parents who are looking to research to see how to “handle” their infant’s behaviour; however, I must be clear that this sample is not typical of the overall population.

Who used it?  Of these 411 parents, 204 (or 49.6%) admitted to having used CC to reduce infant night waking.  Somewhat disturbingly, 70% of the parents who tried it admitted to having tried it before the infant turned six months of age.  For how long?  Although the majority of parents who used CC used it for less than a week (59.3%), a sizeable minority (12.7%) used it for over a month.  I have to add here that this is one of the more distressing pieces of information because clearly there is an infant attempting to communicate to a parent, and a parent who is repeatedly trying the same thing, clearly with no success.

How successful were these parents?  Well, first off, only 16.2% of parents who tried CC only started it once (whether they gave up or it was successful is unknown).  Note: “Starting” it means there was a break in between periods of use when it was not used; therefore, if a parent used it for one week, then stopped for a week, then started again, they would have started it two times.  The remainder started it two or more times, with 47.6% of parents having tried it four or more times.  In terms of global effectiveness (regardless of number of times it was started), only 14.2% of parents said it eliminated night-wakings whereas 41.7% of parents said it did not reduce night-wakings at all (with the remainder in between reducing a little to a lot but not entirely).

So right now we have a method that is highly touted that is, in essence, quite useless in actually helping parents.  From a policy or intervention perspective, these numbers are abysmal.  If we go on with the findings though, it gets worse.  Not only did it simply not work for many families (or require multiple times over extended periods to work), parents reported it was highly stressful for them and their infant (M=4.04/5 and 3.97/5, respectively), even though they felt fairly supported by those close to them (M=3.5/5).

Interestingly, when the researchers looked at the correlations between CC effectiveness and other variables, the most significant relationships came with parent and child stress.  Yes, the more stressed the parent and child were, the more likely the parent was to rate it a success (and this was particularly high for child stress and remained equally as high when other variables were included in a hierarchical regression).  One can’t help but wonder if the stress alone has led parents to report it a success regardless of its actual efficacy.  After all, if you’ve endured hell, you want to admit to getting something out of it, right?

What do we take home from this?

Well, for starters, as the researchers themselves point out, many parents are using CC when it is not suggested.  The fact that a sizeable portion had started prior to six months despite the evidence against such a practice is deeply concerning.  Second, many families may be trying CC because they feel they have to as many families believe that any night waking beyond a certain time frame is “problematic”.  However, as we know from other research[7], this simply isn’t the case.  Night waking is quite common throughout infancy and for a sizeable minority of children, throughout toddlerhood as well.  I myself have written on the numerous reasons why infants and toddlers wake at night and parents may have very misguided expectations of what to expect.  Finally, CC may not work because, as I have pointed out elsewhere (see here), the problem isn’t with sleep, but rather sleep is the symptom that is indicative of a different problem.  If parents do not treat the underlying condition, they will only see sleep improvements if they hit a stage where their child feels so unheard that s/he stops trying to communicate and this can have even greater problems.

Can we please get to a stage where we focus on infant responsiveness?  Where parents are taught not only normative behaviour, but how to look for any problems that may influence sleep and, if necessary, what gentle methods are appropriate for older infants where their sleep remains problematic for the family (even if not the infant).  Finally, can we please focus efforts on changing our societal expectations and policies so that families have the opportunity to do these things?  Sleep training is NOT the answer.

 

[1]

[2] Mindell J, Kuhn B, Lewin DS, Meltzer LJ, Sadeh A, Owens JA.  Behavioral treatment of bedtime problems and night wakings in infants and young children.  Sleep 2006; 29: 1263-76.

[3]Price AMH, Wake M, Ukoumunne OC, Hiscock H.  Five-year follow-up of harms and benefits of behavioral infant sleep intervention: randomized trial.  Pediatrics 2012; doi:10.1542/peds.2011-3467.

[4] Hiscock H, Wake M.  Randomised control trial of behavioural infant sleep intervention to improve infant sleep and maternal mood.  BMJ 2002; 324: 1062.

[5]Loutzenhiser L, Hoffman J, Beatch J.  Parental perceptions of the effectiveness of graduated extinction in reducing infant night-wakings.  Journal of Reproductive and Infant Psychology 2014; http://dx.doi.org/10.1080/02646838.2014.910864.

[6]Douglas PS, Hill PS.  Behavioral sleep interventions in the first six months of life do not improve outcomes for mothers or infants: a systematic review.  J Dev Behav Pediatr 2013; 34: 497-507.

[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.