As promised, here’s a huge pile o’ links to studies that show that CIO has beneficial effects on children, parents and families in general, and some related topics I thought you might find interesting. Keep in mind this is not a recommendation to CIO if you don’t want to – if whatever you’re doing works for you, more power to you. However, if you find your infant’s (preferably>6months) waking at night is causing you grief, you don’t need to feel shamed by the sanctimommies who inhabit certain parenting-messageboards-which-shall-not-be-named , nor certain alarmist parenting “experts”. I’ve tried to link to the full-text articles when available free online.
First of all, it’s been shown in several studies that the one recurring factor for young babies not learning to sleep for stretches (by this I don’t necessarily mean the 9-12 hours straight we might expect of an older baby, but one 4-6 hour stretch by 2-3 months) and not learning self-soothing behavior is falling asleep with a parent present:
Night Waking, Sleep-Wake Organization, and Self-Soothing in the First Year of Life:”Consistent with previous research, this study found that infants who were consistently put into the crib awake were more likely to be self-soothers than infants who were consistently put into the crib asleep. Infants who required parental assistance to fall asleep at the beginning of each night were more likely to require parental assistance upon awakening in the middle of the night.”
Factors Associated With Fragmented Sleep at Night Across Early Childhood:”Parental presence until sleep onset was the factor most strongly associated with not sleeping at least 6 consecutive hours per night at 17 months and 29 months of age.”
Sleeping through the night: a developmental perspective:“By 3 months of age, infants who were put into the crib awake at bedtime and allowed to fall asleep on their own were more likely to return to sleep on their own after awakenings later in the night. In contrast, infants who were put into the crib already asleep at the beginning of the night were significantly more likely to be removed from the crib following a subsequent nighttime awakening…This association was present at 8 months as well.”
Some more interesting factors:”More time awake at night was related to separation distress, frequent daytime crying, dysregulation, co-sleeping with parents, breast feeding, and being put to bed asleep. More frequent waking was related to separation distress, frequent daytime crying, co-sleeping, and breast feeding.”
Lack of sleep (for the baby and his family) has a detrimental effect upon the family as a whole, and on maternal mood and functioning in particular:
Early infant crying and sleeping problems: a pilot study of impact on parental well-being and parent-endorsed strategies for management.:”Problem infant behaviours are associated with poor parental mental health.”
Maternal depression can have adverse effects on infant and stunt their psychological growth:”Postpartum depression at 4 months measured by the Edinburgh Postnatal Depression Scale was found to be strongly associated with toddlers’ fear score/behavioral inhibition at 14 months. Maternal depressive symptoms assessed by the revised 90-item Symptom Checklist at 6 weeks , 4 and 14 months were found to be related to child inhibition as well. Conclusions: Even maternal depression not reaching the level of clinical diagnosis and treatment has an impact on child behavioral development.”
Hmmm…maybe it’s not all that great to run mothers ragged “for the good of the baby”.
However, help is at hand – behavioral modification techniques, including CIO in various forms and impressing even on a small infant that it’s sleep time, not feeding or play time, can be very effective in both improving infants’ sleep quality and Mom’s depressive symptoms. I’ll not that some of these interventions were done on infants significantly younger than the 6-12 months normally recommended for CIO; however, the expectation here was to enable even these small babies to sleep for decent stretches of time (4-6 hours in one period during the night), not the usual “sleeping through the night” we expect of older infants. When your baby is 2 months old and has been waking 10 times a night since birth, even a 4-hour episode of unbroken sleep can seem like sheer heaven.
Randomised controlled trial of behavioural infant sleep intervention to improve infant sleep and maternal mood:”Behavioural intervention significantly reduces infant sleep problems at two but not four months. Maternal report of symptoms of depression decreased significantly at two months, and this was sustained at four months for mothers with high depression scores.”
Does CIO harm the baby and cause him to cry incessantly, thereby permanently damaging his delicate psyche? It appears not:
A systematic review of treatments for settling problems and night waking in young children:”The most controversial aspect of behaviour modification studies is recommending that families leave their infants to cry while “learning” to fall asleep alone. This study found no differences in mean hours of crying between the intervention and control groups.”
Changes in infant sleep problems after a family-centered intervention. : “The intervention was based on correction of day-sleep rhythm, support of self-comforting capabilities of the infant, and education of parents in regard to the infants’ characteristics and developmental status. Changes in day naps and infant irritability over daytime also improved significantly.”
Help me make it through the night: behavioral entrainment of breast-fed infants’ sleep patterns. : “By 3 weeks, treatment infants showed significantly longer sleep episodes at night. By 8 weeks 100% of treatment infants were sleeping through the night compared to 23% of control infants. Treatment infants were feeding less frequently at night but compensated for the relatively long nighttime interval without a feed by consuming more milk in the early morning. Milk intake for 24-hour periods did not differ between groups. Treatment infants were rated as more predictable on Bates’ Infant Characteristics Questionnaire. It is concluded that parents can have a powerful influence on the development of their infants’ sleep patterns. Frequent night waking in breast-fed infants often results in early termination of lactation. Parents can teach their breast-fed infants to lengthen their nighttime sleep bouts, making the continuation of breast-feeding easier for the new mother.” (Ooooh, that last sentence might catch the eye of an APer, won’t it?).
Treatment of sleep problems in families with young children: effects of treatment on family well-being:”Before intervention, the sleep-disturbed children were rated as more insecure than a matched comparison group with unknown sleep behaviour. This difference was eliminated after the interventions. The more anxious the children were rated before intervention, the more they tended to benefit from it.”
Behavior characteristics and security in sleep-disturbed infants treated with extinction :There was no evidence of detrimental effects on the treated infants whose security, emotionality/tension, and likeability scores improved.
I’ll be adding more links that attest to the efficacy and safety of CIO as I find them; feel free to suggest your own.
Added May 9th, 2008: long but thorough review by Dr. Jodi Mindell, et al, about behavioral methods of sleep training.
Added October 22, 2008: See here.
Filed under: Infant sleep |