*Primary author is Angela Braden at Science Mommy
Cry-it-out sleep training has not been proven safe, contrary to what many parenting media report. When we outlined the logical and factual failures typical of such reporting, we got an immediate rebuttal. Here’s why we stand by our original assertions and then some.
Here is the original post, Parents Misled by Cry-It-Out Sleep Training Reports. Here is the rebuttal by Dr. David Rettew, whose PT blog is the ABCs of Child Psychiatry. This post is a responses to his critiques.
Dr. David Rettew took a keen interest in our recent post on the problem of parenting media’s sweeping failures in reporting on cry-it-out sleep training. He seemed to reiterate some of the problems we noted, but also accused us of being overdramatic in voicing our concerns with infant sleep training in general. It is an impassioned issue for us, admittedly, because the cool detachment of sleep training advocates is so alarming from a developmental viewpoint and because we deal with the sad effects of it in our daily work. Passions aside, we stand by the science we presented that supports valid concerns involved in these sleep training practices. We think that pointing out risks is vital to letting parents make informed decisions. And so we take issue with Dr. Rettew’s accusation that we are doing the same thing Parents magazine did.
1. DR. RETTEW: This post makes some strong points, especially about the way that the media and, in turn, the public can make wild conclusions that go far beyond what science actually tells us. Unfortunately, [this post] does exactly the same thing in [its] counter arguments.
RESPONSE: Parents made the sweeping statement “whatever” parents do in terms of leaving their babies to cry-it-out is “just fine.” Scientific studies of sleep training are often detached from meaningful long-term impact and the big picture. They might seem to simplify choices, but they actually often focus attention on the wrong things. We are not making a sweeping generalization about all types of sleep training at any time or age. Rather, we connected the dots that show the real concerns and valid risks—how and why these methods can easily escalate to a traumatic event. We pointed out the importance of attending to age and temperament of the baby, as well as the dangers of toxic distress and why, from an evolutionary perspective, being left alone and ignored feels threatening to a baby. We are not hanging our hat on a single study the way Parents did, but rather we are, point-by-point, revealing how multi-disciplinary science can inform parent’s decisions on this difficult matter.
Please also note the baseline from which we stand (listed at the bottom of the original post): 30-million-year old parenting practices that evolved to fixation because they optimized development in young social mammals (physical proximity and positive touch, responsiveness to the needs of the child, play, multiple responsive caregivers, breastfeeding, positive social support). Going against these practices is species-atypical (e.g., leaving babies alone) with developmental consequences (Konner, 2005). If there is any evidence of possible damage, then the contrary action should not be taken. It means that a precautionary principle should be applied when evidence contrary to baselines is found. This is our view of sleep training babies. The conclusions this baseline suggests are anything but “wild,” as Dr. Rettew suggested.
2. DR. RETTEW: To put my own current opinion on this issue up front, I will say that I do believe that behavioral sleeping techniques such as controlled crying or camping out can be highly effective (often in a matter of days) and do not cause developmental problems. That said, I don’t have any quibble with parents who choose to go comfort children at each awakening or those who choose to share a bed with their kids (especially if over 6 months old). “I also don’t advocate that parents continue to plug away with behavioral techniques indefinitely if they aren’t working.”
RESPONSE: We didn’t assert that all forms are always harmful, but rather, we asserted the inaccuracy of Parents magazine’s statement that cry it out specifically was safe. We also noted that in the case of “controlled crying” methods, the crying is not “controlled.” In other words, it doesn’t work within the baby’s tolerance. When it is, like cry it out, conditioning him not to cry, it can present the same types of risks as cry-it-out. However, to Dr. Rettew’s “do not cause developmental problems”: We don’t know how he can conclude this. Has he examined all possible variables longitudinally? And is he making a sweeping statement that parents could apply to a weeks-old baby, as Parent’s magazine did? (one of our original concerns)
With his second statement, Dr. Rettew beautifully illustrates our point that falls within # 4 in our original post: “I also don’t advocate that parents continue to plug away with behavioral techniques indefinitely if they aren’t working.”
Unfortunately, sleep training books do, in fact, insist that parents continue with the behavior modification techniques indefinitely without “giving in.” This is what makes these techniques effective and this is the problem. Dr. Jodi Mindell, for example, specifically explains in her well known baby sleep manual that if you let a child cry and then cave in, you have not only just made the crying worse in the future, but you have just “had your child cry for nothing.” This is behavioral conditioning not to cry, which is counter to what decades of attachment research shows. Parental response to distress is far from nothing— It’s everything.
Here is point 4 from our original post:
Parenting media fail to recognize the pervasive influence of behavior modification:
… At the same time, the media routinely downplay the role of behaviorist thinking, assuming that parents will use good judgment in carrying out sleep training methods. In doing so they miss that an integral part of the behaviorist approach—the extinction part—specifically requires parents not to use their judgment. For total extinction, they must never “give-in” in order to make their efforts effective in conditioning their baby not to cry. This is the approach the majority of sleep-training books on the parenting shelf promote, to which Parents readers may now turn to in droves.
But even in the loving hands of parents with otherwise good judgment and instincts, the popular baby sleep manuals instruct based on the behavioral conditioning component of cry-it-out. Some of the books start out dealing with gentle ways to encourage sleep; some advise partial extinction or controlled crying; but with few exceptions, they land on: just don’t go back into the nursery . . . no matter how desperate the screaming becomes or how long the baby’s panic state lasts: total extinction.
3. Dr. Rettew’s rebuttal post’s subtitle “What Happens When a Classic Parenting Question Goes Unanswered?” is exactly what our original post outlined. Here’s what happens: Parenting media tell parents “cry it out” is “just fine,” sending them to the sleep-training manuals where they are instructed to enforce techniques that the study Parents cited, the Price study, did not even look at. When this classic parenting question goes unanswered, parenting media answer it inaccurately, resulting in a lot of unnecessary pain for millions of parents and babies.
4. DR. RETTEW: The study in question took an Australian sample of 7-month-old infants . . . this study examined how the kids and mothers were doing 5 years later. The bottom line, according to the authors, was that the families who did and did not get the instructions were not statistically different from each other no matter what was examined (sleep, behavioral problems, parental health, parenting and bonding measures, etc.). The authors concluded that there was no evidence that these techniques caused harm and thus could be recommended to help with the short-term sleeping problems during infancy.
RESPONSE: Here, Dr. Rettew seems to be agreeing with us in his reiteration of the study. We think we may be winning him over. He gets the reporting fallacies: Parenting media lump total extinction in based on the conclusions of the Price study and that’s a big mistake, putting babies at risk for trauma. Again, the newest most popular sleep training book by Jodi Mindell, which is considered a “kinder, gentler version of Ferber,” tells parents to use total extinction if the “gentler” techniques don’t work. She even advocates leaving the baby uncomforted after crying to the point of throwing up (a sign of trauma!). The older editions of popular books like Baby Wise even had parents ignoring a hungry newborn baby on a wildly unnatural four-hour feeding schedule. What if one of the current Parents readers picks up this unfortunate book at the local library and thinks that’s “just fine” too?
5. DR. RETTEW: The post also does point out some valid limitations of the study. The instructions on the sleep techniques were brief and whether or not parents actually used them (in either the intervention or control group) was not assessed, as is customary in most intervention studies. However, it is worth pointing out that group differences were found in the earlier study, suggesting that it is likely that the group receiving the instruction did apply these techniques more than those who did not, as was the study’s intention.
RESPONSE: We are aware that some differences in maternal mental wellbeing were found in the groups when the subjects were toddlers, however, this says nothing about the safety of sleep training for babies. Since the intervention group had more support (from the nurses) this may translate to moms feeling better. In fact, we think one of the most important strategies to thriving in baby’s first year is to surround parents with support and guidance. We just don’t think that guidance should include risky advice, as the current sleep-training instructions do . . . and media state is “just fine.”
6. DR. RETTEW: In a sentence that would be alarming for any parent to read, for example, [they state] that “over 2 million Parents readers have just been told that leaving babies to cry to the point of distress and beyond—to the point of potential neurological damage-has been proven safe and even that it’s proper childrearing.” While one might logically think that the citation given for this claim of neuronal damage would be related to human babies, it actually refers to a study of adult monkeys given the stress hormone cortisol to drink for a month.
RESPONSE: Our statement here actually links to a previous post which deals with the issue of damage to the brain by cortisol. We didn’t want to take up room in this post to reiterate what had already been covered elsewhere. Bottom line: There is a point during distress at which neurological damage occurs, specifically to the hippocampus, prefrontal cortex, and orbitofrontal cortex, which are in the process of forming linkages in infancy. Logically, this means the damage would be considerably greater for babies than adults.
If anyone doubts this brain-damage-from-stress dynamic, we included the link to the previous post as well as several studies cited that should remove any doubt. The Lyons study did show the detrimental effects of prolonged stress on monkeys’ hippocampi using cortisol levels meant to simulate prolonged stress—not even the intense level panicked infants can experience when left to cry. (See Lyons, 2000, cited in the previous post.)
Another study indicates that prolonged exposure to elevated cortisol disrupts selective attention, response inhibition, and performance on prefrontal-dependent tasks (Forget et al., 2000). This is also likely why, if we may connect another dot here, persistent crying in infancy is linked to an increase in ADHD (Wolke, D, et al, 2002), the most prevalent neuropsychological diagnosis among children. If Dr. Rettew still questions that neurological damage as a result of extreme or prolonged distress can apply to babies, we further point to Dr. Allan Schore’s synthesizing work.
Parents also love to know that the opposite action is at work: High-nurturing results in a larger hippocampus. This is illustrated by an exciting recent study by psychiatrists and neuroscientists at Washington University who conducted brain scans on children who had participated in an earlier study as preschoolers. The earlier study identified kids with the most nurturing parents and guess which ones ended up, at age 7, with a hippocampus 10 percent larger than the other children? Yeah, the ones who had the highest nurturing. Some behaviorist perspectives would consider these kids “spoiled” by their parents’ affections. That’s like saying the largest, sweetest, heartiest apple in the bunch was the spoiled one. Sounds crazy, but this is the backward paradigm parents are fed by the media.
And yes, these findings provide evidence that the same phenomenon seen in decades of animal research is also true in humans, like the research on rats: Maternal nurture in early life—manifested as licking and grooming in rats—is linked with larger hippocampi. This results in better memory, learning, and a greater ability to cope with stress. In contrast, maternal neglect (not even abuse) harms the hippocampus and makes rats more prone to the rodent equivalent of depression. (Depression’s effects on preschoolers’ brains have also been documented via brain scans.) Stress matters, especially as the brain is rapidly growing during infancy.
7. DR. RETTEW: Later in the post, there is the sentence “the younger or more sensitive temperamentally the baby is, the faster and higher the stress level will rise when suddenly left alone to sleep, and the greater damage done to the child’s developing brain.” The reference here is actually a study about rat mothers’ licking and grooming behavior.
RESPONSE: When you read the study, beyond noting that it deals with rats, you see that it shows that variations in maternal care in early postnatal life are associated with the development of individual differences in behavior and the stress response system. In other words, how well the baby’s stress is regulated by the mother determines how a mammal’s stress response system is set—for life. These stress systems are the same for all mammals, so we can’t dismiss animal studies that show this dynamic at work. As Dr. Rettew acknowledges—animal studies are relevant.
This study is especially relevant also because it shows that it’s not just extreme abuse and neglect that cause negative outcomes, but “variations in care,” including what we refer to as “under care.” Under care essentially programs the nervous system for chronic anxiety, lower resiliency, and higher mental health risks. This supports our original point that effects of neglect are on a continuum.
Dr. Rettew is right in pointing out that this is just one piece of evidence dealing with one detrimental effect. We did not mean for the Caldji study to be seen as the only source of this assertion, just a very telling one. Rather, we attempted to lay out a big picture of the risks of cry-it-out, particularly for a young baby. Our # 1 and #7 provide more support and more detailed explanations of how intense stress specifically affects brain development, in addition to how the stress-response system sets up. And these references do include human studies. Again, we are connecting the dots for parents. Our #5 explains why it ignored crying can be experienced as trauma and evoke a strong hyperarousal then dissociative response; then #7 explains the effects of such a response. Both of these points have bodies of scientific support, not only one study. This speaks to our primary concern with the parenting media’s reporting. You have to look at the big picture when advising on this difficult issue, not one flawed study.
8. DR. RETTEW: Finally there is the sentence, “Infants can experience PTSD, toxic distress, depression and dissociation in response to crying-it-out.” Here the link is not to a study that demonstrates this (because there isn’t any) but to a review article by a psychiatrist who has marketed an approach to traumatized children that itself has been criticized for not being adequately researched before being sold to the public. Certainly, animal data is not irrelevant to humans, but to make such specific and provocative claims such as those made here and then cite rat licking as the primary source is needlessly alarming and heavily misleading.
RESPONSE: Are we to take from this that Dr. Rettew doesn’t believe infants can experience PTSD, toxic distress and dissociation? The reason we cited Dr. Bruce Perry’s review paper is that we consider it an early, accessible gem. Dr. Perry also writes books for the public and so can be accessed by readers (see below for a link). But this was just a sample paper. There are many more papers that provide converging evidence on the impact of trauma in early life. One comprehensive resource is the book edited by respected scholars, Ruth Lanius, Eric Vermetten and Clare Pain: The Impact of Early Life Trauma on Health and Disease: The Hidden Epidemic.
The efficacy of Dr. Perry’s approach (which is brilliant) in dealing with trauma is beside the point. Perry’s research and analysis of how child trauma works, much of it based on his neurodevelopmental analysis of studies of Romanian Orphans who were ignored as babies (these orphans were humans! And so were the numerous children Perry has treated, as chronicled in his illuminating books).Perry’s work in this area is substantial and is clearly supportive of our presentation of how infants react to extreme stress..
If Dr. Rettew does accept that infants can experience these effects, like every neuroscientist we know, then all he has to do is connect that to an understanding of the baby’s stress response when suddenly being left alone in a room with his cries unanswered. This “dot” is connected (and supported) in #7 and in #5 of our original post:
Being left alone at all is stressful for baby mammals (Levine, 2005). Their biological systems become disorganized when separated from caregivers because they have no sense of safety apart from adults. When their distress calls (cries) are then ignored they instinctually panic—their lifeline is gone. (More on the brain’s Separation distress neuro-circuitry.) Once we understand that babies are operating from a survival instinct-dominant, immature brain with limited ability to rationalize, the plentiful trauma research clearly applies. Infants can experience PTSD, toxic distress, depression and dissociation in response to crying-it-out.
This is how distress (signaled by crying) becomes trauma.
We are at a loss as to how anyone can fail to recognize how being left alone and ignored when you are completely helpless and you are desperately calling for reassurance that your lifeline still exists could be experienced as trauma. But, okay, there are multiple studies we quote in other posts on early stress and sleep training (see list below). And here’s a quote from another recent paper on early life stress:
“Levine’s (2005) [argued] that lack or loss of species typical parental stimulation is among the most potent stressors early in life. A focus on deprivation or loss as a potent stressor is consistent with Hofer’s (1994) concept of hidden regulators embedded in parent-offspring relationships. He has argued that a number of sensorimotor, thermal, and nutrient-based events that are components of typical parent-offspring interactions have long-tem regulatory effects on specific components of infant behavior and physiology. Loss of these hidden regulators results in wide-spread dysregulation of physiological and behavioral responses during development resulting in disturbances in circadian rhythms, growth (including brain growth factors, e.g. Cirulli et al., 2000, and Cirulli, 2010) and hormone levels (including activity of the hypothalamic-pituitary-adrenocortical [HPA] axis, e.g. Rosenfeld et al., 1992). Animal studies also point to circuits involved in threat- and stress-system functioning as particularly sensitive to disturbances inparental nurturance (see review, Sanchez et al., 2001). Importantly, though, recent rodent studies also indicate that later interventions may help ameliorate some (but not all) of the impact of poor early nurturance (Bredy et al., 2003; Francis et al., 2002).”
9. DR. RETTEW: Ironically, Ferber used to claim that NOT applying behavioral sleep techniques would cause psychological damage because a child would never learn how to soothe him or herself. He has backed off on this assertion because of a lack of evidence.
RESPONSE: Ferber may have backed off of this assertion, but its influence still lingers as evidenced by the Parents article’s second assault—your baby “NEEDS to learn to fall asleep by himself.” Again, the role of behavior modification’s influence on parents is minimized, but when you read the sleep training books, you see it’s all too alive and well. And this is our concern.
10. DR. LETTEW: To me it is quite possible that these techniques when applied the right way at the right time do not result in damage. . . . All of us would be well to remember that scientific evidence is there to inform our opinions, not justify them.
RESPONSE: Wow, this seems like a concession. If it’s only “quite possible,” as he says, that “if” done “in the right way at the right time” it could magically avert the natural responses and outcomes that science shows us is the norm, then is it responsible to state “whatever” is “just fine” as media often does? Dr. Lettew makes precisely our point here. Bodies of research suggest this practice should be viewed as potentially harmful until proven otherwise. The Price study doesn’t prove otherwise by any stretch, yet Parents (and many other media) conclude that it supports the safety of cry it out. If, as Dr. Rettew suggests, there’s some remote possibility that some behavioral methods (he seems to agree, not total extinction or cry it out) could be done safely, that has yet to be supported empirically. But the bigger problem is that methods the media are driving parents toward are clearly NOT “the right way at the right time.” They are pointed toward the popular baby-training manuals inspired by behavior modification. And these are wrought with risks. We think this is irresponsible reporting—that was the opinion of our post and we feel it is well justified.
Again, Dr. Rettew is very close to our side of the issue here. With a bit more connecting of dots, we hope we can win him over. It’s a worthy cause.
Or post a sleep question on her Facebook page.
Forget H, Lacroiz A, Somma M, Cohen H (2000) “Cognitive decline in patients with Cushing’s syndrome.” Journal Int Neuropsychology Soc 6:20 –29,
Konner M. (2005). “Hunter-gatherer infancy and childhood: The !Kung and others. In: Hunter-gatherer childhoods: Evolutionary, developmental and cultural perspectives.” BS Hewlett and ME Lamb (eds). New Brunswick: Transaction Publishers.
Wolke, D, et al, (2002) Persistent Infant Crying and Hyperactivity Problems in Middle Childhood, Pediatrics; 109:1054-1060.
Links to other posts on infant sleep and sleep training: