Another prospective study performed temperament assessments at the ages of three and twelve months. At three months, the extremely fussy/colicky infants were more intense, more persistent, less distractible, and more negative in their mood. However, at twelve months, ratings on the temperament questionnaire showed no group differences between the extremely fussy/colicky infants and the control group, but the general impression of the mothers of the colicky group was that they were more difficult.
Infants who had extreme fussiness/colic, using Dr. Wessel's criteria, are more likely to have a difficult temperament than noncolicky babies when the temperament assessment is performed at four months of age. Furthermore, this progression occurs even when extreme fussiness/colic is successfully treated with the drug dicyclomine hydrochloride. This drug may act centrally in the nervous system or relieve smooth muscle spasms of the gastrointestinal tract. Similar results were observed in another study: While behavioral management significantly reduced evening fussing and crying, there were no effects of successful treatment on later temperament ratings; the infants were still described as difficult. These results originally suggested to me that biological factors cause increased cry/fuss behavior during the first three to four months of age and subsequently lead to difficult temperament assessments. I then thought that colic-induced parental distress or fatigue was a much less important factor. Now I have a slightly different view that I will share later.
Extreme fussiness/colic does not appear to be an expression of a permanently difficult temperament. In one study of extremely fussy/colicky infants, subsequent measurements of temperament at five and ten months did not show group differences between formerly extremely fussy/colicky and common fussy/ crying infants.
Sleep Temperament
Continuous recordings of sleep patterns during the second day of life were linked with temperament assessments at eight months. It was observed that infants with the most extreme values on all sleep variables were more likely to have difficult temperaments.
Temperament assessments performed at a mean age of 3.6 months showed an association between problems of sleep/ wake organization, difficult temperament, and extreme crying. Mothers of crying infants scored high on depression, anxiety, exhaustion, anger, adverse childhood memories, and marital distress. The authors concluded that factors related to parental care, while not causing persistent crying, did function to maintain or worsen the behavior. The persistence of parental factors may explain why at one year there is reported to be more difficulty in communication, more unresolved conflicts, more dissatisfaction, and greater lack of empathy in families with an extremely fussy/colicky infant, and after four years, formerly extremely fussy/colicky children have been reported to be more negative in mood on temperament assessments.
In my study of sixty five-month-old infants, the infants rated as difficult had average sleep times substantially less when compared to the infants rated as easy (12.3 versus 15.6 hours). Although nine infant-temperament characteristics were measured, only five are used to establish the temperament diagnosis of difficult. Four of these (mood, adaptability, rhythmicity, and approach/withdrawal) were highly associated with total sleep duration.
When my original study of sixty five-month-old infants was extended to include 105 infants, those with difficult temperaments slept 12.8 hours and those with easy temperaments slept 14.9 hours. This observation was subsequently confirmed in another ethnic group with different parenting practices. It thus appears that infants who have a difficult temperament have briefer total sleep durations when assessed at four to five months of age.
Support for a sleep-temperament association is also based on a study where objective measures of sleep/wake organization, derived from time-lapse video recordings, were compared with parental perceptions of infant temperament at six months of age. Dr. Keener stated that “Infants considered [temperamentally] easy have longer sleep periods and spend less time out of the crib for caretaking interventions during the night.” However, the authors’ analysis also led them to the conclusion that the night waking is also caused by environmental (parental) rather that biological factors. This increased time out of the crib for temperamentally more difficult children at six months is similar to the observation that increased night waking occurs in formerly extremely fussy/colicky infants at four, eight, and twelve months.
Utilizing a computerized movement detector, it was observed that for twelve-month-old children, those with the temperament trait of increased rhythmicity went to sleep earlier and had longer sleep durations, and by eighteen months of age there was again the observation that both subjective and objective improved sleep measures were associated with easier temperament assessments.
The exact same sixty infants that I examined at four months of age were restudied at three years. Again, temperamentally easy children had longer sleep durations compared to children with more difficult temperaments. However, there was no individual stability of temperament or sleep durations between the ages of four months and three years. Thus, temperament ratings and associated sleep patterns at age four months do not predict temperament or sleep patterns at three years.
Postcolic Sleep
I did another study of 141 infants between four to eight months of age from middle-class families and showed that the history of extreme fussiness/colic was associated with the parents’ judgment that night waking was a current problem. The frequency of awakening was a problem in 76 percent of infants, the duration of awakenings a problem in 8 percent, and both frequency and duration a problem in 16 percent. The more often a child woke up the longer were the durations of the night wakings. Other studies also reported more night waking at eight and twelve months and ages fourteen to eighteen months in postcolic children. Among those postcolic infants, the total sleep duration was less (13.5 versus 14.3 hours). These group differences decrease as children become older.
There are studies suggesting that both infant irritability and sleep deficits are moderately stable individual characteristics during the first year of life and beyond. One study showed that children with extreme fussiness/colic had more sleeping problems and the families exhibited more distress than a control group at age three years. The trend of decreasing group differences with age regarding sleep between colicky and non-colicky infants and the normal sleep lab recordings of colicky infants at nine weeks of age suggest that it is not biological factors that contribute to enduring sleep problems beyond nine weeks of age, it is parenting practices.
It may be difficult for parents of postcolicky infants after four months of age to eliminate frequent night wakings and lengthen sleep durations. Because of parental fatigue, parents may unintentionally become inconsistent and irregular in their responses to their infant.
It cannot be overemphasized that, as stated by Dr. Parmelee, “Parents are never truly prepared for the degree to which the babies' sleep/wake patterns will dominate and completely disrupt their daily activities.”
They may become overindulgent and oversolicitous regarding night wakings and not appreciate that they are inadvertently depriving their child of the opportunity to learn how to fall asleep unassisted. Some mothers have difficulty separating from their child especially at night, while other mothers have a tendency toward depression, which might be aggravated by the fatigue that results from struggling to cope with a colicky infant. In either case, simplistic suggestions to help the child sleep better often fail to motivate a change in parental behavior. If a child fails to learn to fall sleep unassisted, the result is sleep fragmentation or sleep deprivation driven by intermittent positive parental reinforcement. This causes fatigue-driven fussiness long after the colic has resolved, which ultimately creates an overtired family.
Support for this view has come from research on infants at five months of age who were followed to fifty-six months of age. Dr. WoIke showed that “Long crying duration and having felt distressed about crying during the first five months were significant predictors of night waking problems
at twenty months” but not at fifty-six months. In other words, the combined factors of long infant crying or fussing plus parental distress at five months of age make it more likely that a night-waking problem will develop. Even more powerful, later sleep problems are mostly related to the comorbidity or linking of crying with sleep problems at five months rather than to crying problems alone. Sleep problems at five months remain the best predictor of sleep problems, especially night waking, at twenty months. Dr. Wolke concluded that postcolic “sleep problems are likely to be due to a failure of the parents to establish and maintain regular sleep schedules. … This conclusion does not blame parents for sleep difficulties. Rather, it recognizes why many parents adopt strategies to deal with night waking in the least conflictual manner by night feeding or cosleeping. This may be especially true of parents who are dealing with a temperamentally more difficult infant.” The authors also concluded that postcolic sleeping problems are not due simply to increased crying per se, but appear to be the consequence of associated infant sleeping problems and altered caretaking patterns for dealing with night waking in infancy.
Dr. Bates and associates recently directly evaluated the interaction between family stress, family management, disrupted child sleep patterns (variability in amounts of sleep, variability in bedtime, and lateness of bedtime), and adjustment in preschool in children about five years old. Children with disrupted sleep did not adjust well in preschool. In their analysis, disrupted sleep directly caused the behavior problems. They did not find any evidence that family stress or family management problems caused both disrupted sleep and behavior problems. Dr. Bates concluded that “sleep irregularity accounted for variation in [behavioral] adjustment independently of variation in family stress and family management.” Dr. Bates agrees with my hypothesis that sleep modulates temperament and told me that “parenting responses to [sleep] issues would be involved in the continuity/discontinuity of temperament…. If parents make the effort to manage their kids’ sleep schedules consistently, I would think that over the years they are going to see less difficult and unmanageable behavior.” Another recent study examined sixty-four children, aged eight to ten years, who had, as infants, “persistent crying” defined as fussing or crying more than three hours on three days in the week. The authors concluded that they were at risk for hyperactivity problems and academic difficulties. In addition, at eight to ten years of age, the previous persistent criers took a longer time to fall asleep, suggesting to Dr. Wolke that “they were less effective in controlling their own behavioral state to fall asleep.”
Therefore, it appears that the increased crying/fussing behavior in infancy is associated with less infant sleep, and the crying/fussing alone does not directly cause later sleep problems. Although the postcolicky child's family may be stressed, it appears that it is the failure to establish age appropriate sleep hygiene that specifically leads to later disrupted sleep and behavioral problems.
Summary
During the first four months, colicky infants, by definition, exhibit more cry/fuss behavior. Data from parent diaries obtained at four and a half, six, seven, and eight weeks of age show that extremely fussy/colicky infants sleep less than common fussy/crying infants (about 12-12.5 versus about 14-14.5 hours), but there is disagreement as to whether the decreased sleep occurs predominately during the day or night hours. By nine weeks of age, sleep lab data does not show group differences regarding sleeping between extremely fussy/colicky and common fussy/crying infants. Group differences in sleeping duration between these two groups of infants, while present even at four months of age, disappear by six to eight months. This raises the suggestion that parenting practices might be especially important in affecting sleep patterns after nine weeks, especially regarding the development of a night-waking habit. Also, by six months of age, researchers are more apt to describe parents contributing to sleeping problems, especially night waking.
There appears to be agreement that infant crying alone does not predict the development of sleep problems. Rather the comorbidity of crying plus parental distress at five months or crying plus sleep problems at five months predicts night waking at twenty months, but not at fifty-six months.
Temperament assessments at two and four weeks of age showed that infant difficultness predicted increased crying/ fussing at about six weeks of age. Infants with extreme fussiness/colic are more likely to have a difficult temperament when assessed at four months of age, but not at twelve months. A difficult temperament is associated, at many ages, with problems in sleeping, such as shorter sleep durations and night waking, but this association is not predictive of later sleep problems. At four to five months of age, infants with a difficult temperament have total sleep durations of about thirteen hours versus about fifteen hours for infants with an easy temperament.
The association of difficult temperament and sleeping problems during and shortly after four months occurs despite successful treatment of colic. My revised view is that it is exactly those parents who have the willingness and resources to invest heavily in soothing during periods of fussing, who are able to prevent some of the fussing escalating into crying and to prevent some postcolic sleep problems. On the other hand, some parents are unable to manage severe infant fussing and become overwhelmed by crying. They feel they cannot influence their child's behavior regarding crying and, later, sleeping.
It is important for parents to help postcolicky infants establish healthy sleep habits. Some of these children have difficulties falling asleep and staying asleep. At about four months they have not developed self-soothing skills, perhaps because parents had invested constant soothing to prevent fussiness developing into crying, or perhaps the inability to self-soothe is an integral component of colic. A successful intervention effort to help families cope with infant crying during colic will reduce parental distress. Continued age-appropriate sleep hygiene after colic ends is likely to prevent sleep problems persisting beyond four months. Unsuccessful intervention increases the likelihood that temperament issues, family stress, and sleeping problems will persist beyond four months.
Here is one vivid personal account of extreme fussiness/ colic.
A FATHER REMEMBERS COLIC; OR, Is THE FRENCH FOREIGN LEGION ACCEPTING APPLICATIONS?
Sleep? Hmmm … Oh, yes! I remember that! We used to do that frequently before Michelle was born.
Two years and another baby later, I still replay Michelle's birth in my mind at least daily. I joked in the delivery room that the newborn was “ugly,” but it was just a ruse to help me hold back the tears. A healthy, normal baby! The demons of the past nine months disappeared in a flash.
The first few days were spectacular. While my wife and baby recovered in the hospital from a long, tough, toxemic labor; I played the role of red-eyed, tired-but-ecstatic new father to the hilt. I showed up at work the next day, ostensibly to guard against using up a vacation day, but actually to show off the Polaroid pictures I had carried home with me in the wee hours of that postpartum morning to avoid waiting an ungodly twenty-four hours for the 35-millimeter prints to be developed.
Everything was perfect. I was getting the house in shape, making the phone calls, bringing goodies to the hospital. Nursing was starting off fine for my wife, Sharon, and our new baby was peaceful and thriving.
The false security even lasted through the first few days Sharon and Michelle were home. Michelle would wake up about every three or four hours and, with a tiny, delicate cry, let us know that it was time to nurse again. We marveled at the fact that no matter how soft the cry or what room it came from, we could always hear it. Isn't parenthood amazing? And as Michelle nursed, she would usually doze off again. When Sharon was finished, she'd put the baby back in her crib, and we would just stare down at her, enjoying the peaceful sight of our sleeping baby.
Just as Michelle crossed the boundary into her second week of life, the scene started to change. Same little cry. Same nursing routine. But then, when the nursing stopped, a new cry would start.
This one was different. Louder. More agitated. More demanding. I rather enjoyed it at first, because it gave me a role—I could pick her up—and with a few minutes of rocking and patting, the crying would stop. It was my first fleeting sense of competence as a father.
But the crying grew worse and worse. Five minutes of rocking were replaced by hour-long midnight jaunts in the stroller. On rainy nights I'd carry her around the kitchen-to-dining-room-to-living-room-to-kitchen circuit so many times that I actually started to vary my route for fear of embedding a path in the carpet. The left shoulder of every T-shirt I owned had spit-up stains on it. I switched to the football carry: Holding Michelle facedown on her tummy with my fingers supporting her chin, I would swing from my hips, back and forth, back and forth, back and forth. At 3:00 A.M. I would strap on the Snugli and set off for another trek with my frantic daughter.
Each of these strategies worked for a short time. But Michelle had become a motion junkie. Absent motion, she would shriek and scream violently and tirelessly, literally for hours at a time. She would become hoarse, but even that failed to deter her.
Everyone we knew had a theory, even people we had only just met in the supermarket checkout line. All the advice was offered freely and generously, but never without the subliminal undercurrent that the real problem was our incompetence as parents. The baby was nursing too much. She wasn't getting enough food from nursing, so we should give her formula. Mix some cereal in with the formula. Wait four hours between feedings. Put her on a schedule. Relax, she senses your stress. And on and on and on. There was no end to the advice, all of it contradictory, much of it accusatory, and none of it helpful.
Healthy Sleep Habits, Happy Child Page 17