By Pinky McKay

Although many baby sleep trainers claim there is no
evidence of harm from practices such as controlled crying,
it is worth noting that there is a vast difference between
‘no evidence of harm’ and ‘evidence of no harm’.

A policy statement on controlled crying issued by the
Australian Association of Infant Mental Health (AAIMHI)
advises, ‘Controlled crying is not consistent with what
infants need for their optimal emotional and psychological
health, and may have unintended negative consequences.’
According to AAIMHI, ‘There have been no studies, such
as sleep laboratory studies, to our knowledge, that assess
the physiological stress levels of infants who undergo
controlled crying, or its emotional or psychological impact
on the developing child.’

Despite the popularity of controlled crying, it is not
an evidence-based practice. In a talk at the International
Association of Infant Mental Health 9th World Congress
held in Melbourne in 2004, Professor James McKenna,
director of the Mother–Baby Behavioural Sleep Laboratory
at the University of Notre Dame, Indiana, and acclaimed
SIDS expert, described controlled crying as ‘social ideology
masquerading as science’.

What this means is that despite a plethora of opinions
on how long you should leave your baby to cry in order to
train her to sleep, nobody has studied exactly how long it
is safe to leave a baby to cry, if at all.

Babies who are forced to sleep alone (or cry, because
many do not sleep) for hours may miss out on both adequate
nutrition and sensory stimulation such as touch,
which is as important as food for infant development.
Leaving a baby to ‘cry it out’ in order to enforce a strict
routine when the baby may, in fact, be hungry, is similar to
expecting an adult to adopt a strenuous exercise program
accompanied by a reduced food intake. The result of
expending energy through crying while being deprived
of food is likely to be weight loss and failure to thrive.
Paediatrician William Sears has claimed that ‘babies
who are “trained” not to express their needs may appear to
be docile, compliant or “good” babies. Yet, these babies
could be depressed babies who are shutting down the
expression of their needs.’

Babies can indeed be ‘brand new and blue’ with an
actual diagnosis of clinical depression. Often the predisposing
conditions for depression in infants are beyond
our control, such as trauma due to early hospitalisation
and medical treatments. However, if we consider the baby’s
perspective, it is easy to understand how extremely rigid
regimes can also be associated with infant depression and
why it isn’t worth risking, especially if your child has
already experienced early separation. You too would withdraw
and become sad if the people you loved avoided eye
contact, as some sleep training techniques advise, and
repeatedly ignored your cries.

Leaving a baby to cry evokes physiological responses
that increase stress hormones. Crying infants experience
an increase in heart rate, body temperature and blood
pressure. These reactions are likely to result in overheating
and, along with vomiting due to extreme distress, could
pose a potential risk of SIDS in vulnerable infants.
There may also be longer-term emotional effects.
Babies need our help to learn how to regulate their emotions,
meaning that when we respond to and soothe their
cries, we help them understand that when they are upset,
they can calm down. On the other hand, when infants are
left alone to cry it out, they fail to develop the understanding
that they can regulate their own emotions. There is
also compelling evidence that increased levels of stress
hormones may cause permanent changes in the stress responses
of the infant’s developing brain. These changes
then affect memory, attention, and emotion, and can trigger
an elevated response to stress throughout life, including
a predisposition to later anxiety and depressive disorders.
English psychotherapist, Sue Gerhardt, author of Why
Love Matters: How Affection Shapes a Baby’s Brain, explains
that when a baby is upset, the hypothalamus produces
cortisol. In normal amounts cortisol is fine, but if a baby is
exposed for too long or too often to stressful situations
(such as being left to cry) its brain becomes flooded with
cortisol and it will then either over- or under-produce
cortisol whenever the child is exposed to stress. Too much
cortisol is linked to depression and fearfulness; too little to
emotional detachment and aggression.

Stress levels in infancy may have implications for
learning, too. While it seems fairly obvious that a calm
baby will be available for learning, studies have shown
that children with the lowest scores on mental and motor
ability tests were those with the highest cortisol levels in
their blood. There is also research showing that children
with anxiety disorders have a higher level of sleep difficulties as infants.
Although these studies weren’t about
controlled crying and I am making no direct connection,
my point is that perhaps some of the babies who are presenting
with sleep difficulties are infants who need extra
help to regulate their emotions or are more sensitive to
stress, so it is possible that these little people would be
more at risk if they were exposed to controlled crying.

One of the arguments for using controlled crying is
that it ‘works’, but perhaps the definition of success needs
to be examined more closely. In the small number of studies
undertaken, while most babies will indeed stop waking
when they are left to cry, ‘success’ varies from an extra
hour’s sleep each night to little difference between babies
who underwent sleep training and those who didn’t, eight
weeks later. Some studies found that up to one-third of
the babies who underwent controlled crying ‘failed sleep
school’. A recent Australian baby magazine survey revealed
that although 57 per cent of mothers who responded to the
survey had tried controlled crying, 27 per cent reported no
success, 27 per cent found it worked for one or two nights,
and only 8 per cent found that controlled crying worked
for longer than a week. To me, this suggests that even if
harsher regimes work initially, babies are likely to start
waking again as they reach new developmental stages
or conversely, they may become more settled and sleep
(without any intervention) as they reach appropriate developmental
levels.

Controlled crying and other similar regimes may indeed
work to produce a self-soothing, solitary sleeping infant.
However, the trade-off could be an anxious, clingy or
hyper-vigilant child or even worse, a child whose trust is
broken. Unfortunately, we can’t measure attributes such as
trust and empathy which are the basic skills for forming
all relationships. We can’t, for instance, give a child a trust
quotient like we can give him an intelligence quotient. One
of the saddest emails I have received was from a mother
who did controlled crying with her one-year-old toddler.

“After a week of controlled crying he slept, but he stopped
talking (he was saying single words). For the past year, he
has refused all physical contact from me. If he hurts himself,
he goes to his older brother (a preschooler) for comfort.
I feel devastated that I have betrayed my child.”

It is the very principle that makes controlled crying ‘work’
that is of greatest concern: when controlled crying ‘succeeds’
in teaching a baby to fall asleep alone, it is due to a
process that neurobiologist Bruce Perry calls the ‘defeat
response’. Normally, when humans feel threatened, our
bodies flood with stress hormones and we go into ‘fight’ or
‘flight’. However, babies can’t fight and they can’t flee, so
they communicate their distress by crying. When infant
cries are ignored, this trauma elicits a ‘freeze’ or ‘defeat’
response. Babies eventually abandon their crying as the
nervous system shuts down the emotional pain and
the striving to reach out.

One explanation for the success of ‘crying it out’ is that
when an infant’s defeat response is triggered often enough,
the child will become habituated to this. That is, each time
the child is left to cry, he ‘switches’ more quickly to this
response. This is why babies may cry for say, an hour the
first night, twenty minutes the following night and fall
asleep almost immediately on the third night (if you are
‘lucky’). They are ‘switching off’ (and sleeping) more quickly,
not learning a legitimate skill.

Whether sleep ‘success’ is due to behavioural principles
(that is, a lack of ‘rewards’ when baby wakes) or whether
the baby is overwhelmed by a stress reaction, the saddest
risk of all is that as he tries to communicate in the only
way available to him, the baby who is left to cry in order to
teach him to sleep will learn a much crueler lesson – that
he cannot make a difference, so what is the point of reaching
out. This is learned helplessness.

This is an edited extract from “Sleeping Like a Baby” by Pinky McKay (Penguin). Pinky is am International Board Certified Lactation Consultant, Certified Infant Massage Instructor  and mother of five.  Visit her website www.pinky-mychild.com.