"To sleep, perchance to dream," says poor Hamlet, obsessing about sleep, and also about death. By the time my daughter was eight months old, I knew how he felt. On a good night she would wake three times; on a bad night, six. Until I had a baby, I had no real idea what a profound lack of sleep actually feels like. "Torture," supplied my best friend, a doctor (and a mother). "It's a recognised form of torture."
There are as many theories about making babies sleep as there are stars in the sky, to use a cliché (which is all you're capable of, after eight months of no sleep). But the vast majority offer some variation of controlled crying. The basic philosophy is that leaving healthy, clean, well-fed babies to cry for varying amounts of time until they fall asleep on their own is physiologically and psychologically okay.
There are varying degrees of severity along the controlled-crying spectrum. At one end is "extinction" (also known as "crying it out"), whereby you simply close the door on your baby and come back in the morning. In the middle are all sorts of techniques, where you return and briefly comfort your baby, usually with increasing stretches of time between visits - five minutes, 10, 15 and so on. Finally, there's "adult fading" or "camping out", where you remain in your baby's room, but over many nights you move, in a kind of glacier-creep, towards the door.
Whatever variant you use, controlled crying is big business. It's easy to teach, and if it works, it generally works fast: within a week for most babies. The two best-selling baby-sleep authors worldwide, Gina Ford (a maternity nurse with no formal qualifications) and Dr Richard Ferber (a Harvard professor of neurology), both advocate variants of controlled crying, and have each sold about a million copies of their books. In Australia, everyone from widely respected individuals like Baby Love author Robin Barker to government-funded clinics and websites support it.
Nobody says controlled crying is easy, of course. Most parents hate listening to their baby scream.
But what are your alternatives? Well, according to no-cry advocates like Elizabeth Pantley or Pinky McKay, you can co-sleep with your baby, or comfort them without letting them cry. But even the staunchest no-criers acknowledge that these methods take a long time, a lot of patience and require high sensitivity to baby behaviour.
In my case, my partner and I tried a bit of everything. We tried co-sleeping. We tried no-cry techniques. We tried controlled crying - but the longest we could stick it out was 10 minutes, and then we almost always comforted her to sleep.
In the midst of this hell, I read Baby on Board, by Howard Chilton. Chilton is a paediatrician based at Sydney's Prince of Wales Private Hospital and Royal Hospital for Women.He was director of the neonatal unit at RHW from 1978 to 2000, when he left to focus on clinical work, his writing (his most recent book, Your Cherished Baby, was published last year) and the practice of what he calls "reassurology".
"What I don't like about controlled crying is this default reaction," he says. "This belief that babies have a 'sensitive window', and if you don't 'teach' them to sleep, they'll never learn and they'll always wake up." He laughs. "It's a good story to scare parents and make them buy your book! But it doesn't happen to be true."
So what is true? Are there any scientific, uncontested facts about baby sleep?
Yes. And for Chilton, fact one is that, thanks to the evolution of our narrow, twisted pelvises (to assist upright walking) and our babies' large heads (to accommodate big brains), all human babies are born developmentally premature, and, like premature infants of any species, need a lot of high-intensity, contact-based care for a long time.
Fact two is that standard baby nourishment - breast milk - is very low in protein, so it's digested quickly and needs replacing frequently. These two facts alone - high care and frequent feeding requirements - suggest that young babies are unlikely to be much good at lying peacefully in a room on their own for 12 hours.
Fact three. Until six months, babies have no grasp of object permanence. They cannot understand that when an object is removed from their sight, it still exists. So if a parent leaves, they have, in the baby's mind, gone forever. Cue panic.
Fact four. Contrary to what many controlled-crying techniques suggest, prior to six months, babies cannot "learn" to sleep on their own. "They have no learning centres in their brains [yet]. In terms of a reproducible result - 'We've done this today, so this is my understanding of what will happen tomorrow' - that just doesn't happen before six months," Chilton says.
So what about the success stories with babies younger than six months? I know a mother who implemented a controlled-crying regimen when her daughter was three months old. It was horrible, she said, but by four months, her daughter was sleeping through most nights.
"Before six months, you're just extinguishing," explains Chilton matter-of-factly. "Eventually, the baby just gives up."
Fact five: "extinguishment" is the name given to evolution's last effort at infant survival in extremis. Loss of parental contact is a serious danger signal for young babies, and they're designed to cry and cry until it's restored. But beyond a certain point, even a hysterical baby will stop crying, often quite suddenly. This is because, in an evolutionary sense, an unprotected crying baby is broadcasting its whereabouts to predators. Instinct tells it that its parents have vanished, and that the sabre-toothed tiger that killed them is close. It falls silent in order to survive.
It's thought, however, that such a baby is still under stress. In one 2012 study of controlled crying in babies as young as four months, researchers found that by the third day of the program, babies had stopped crying at sleep times, but their levels of the stress hormone cortisol were elevated.
Of course, many parents never have to think about studies like this, and what these results may suggest about what's happening to their babies. Some babies are naturally great sleepers. But as many as 40 per cent of babies continue to wake through the night past a year; for the parents of these babies, what's the bottom line?
Jo* is a very positive, warm-sounding woman in her mid-30s. She lives in rural NSW, and when she gave birth to her first son, she took a very natural approach to sleep. "But with our second, there were a lot of mums in our area using a kind of 'cry-it-out' method, and I guess I was led to believe by them that my first son's sleep wasn't great; that I should do better with my second."
"So my second son, Ben*, was born, and he was a completely wonderful sleeper - from 8pm till 4am, sort of thing. But nevertheless, when he was three months old, I started this 'wonderful' routine."
Within three or four weeks, Ben "was more often than not crying himself to sleep while I sat outside the room and cried as well. Within two months, we had a baby who was waking five or six times a night; a baby who was petrified to go to bed; would not let himself go to sleep anywhere else but in his cot: never in the car, never in the pram. So the sleep training that was supposed to maintain this wonderful sleep absolutely destroyed his sleep."
Jo stopped the routine after four months, but "I feel it has caused damage," she says. At 18 months old, Ben was diagnosed as having a sensory processing disorder. Part of this problem may have existed at birth, says Jo, "but at the very least, controlled crying has exacerbated sensitivities that were there."
Howard Chilton would agree. "It's a question of brain development," he says, leaning forward. "When you're born, you're just a limbic brain. That's the threat-and-reward part of the brain: it responds to fear, food, contact. Whereas the frontal lobes - the intelligent, thinking part of your brain - are not connected at all."
"During your first year of life, you wire up connections between your limbic system and the frontal lobes which help you regulate stress, and establish your feelings of security and self-worth. There are up to a thousand connections a second being made in your first 12 months. Part of that wiring-up is genetic. But part of it is environmental ... Stress is part of your environment, and it triggers the release of stress hormones like cortisol and adrenaline. Cortisol, particularly, has a really negative effect on neural connections."
So our brains are being permanently shaped, at least in part, by how we're being comforted at night, before we're even one year old? "After 12 months, it's in your hardware. You can modify the basic system, but it takes a great deal of deep cognitive work - and I often wonder how good any rewiring actually is. The basic stuff about stress is done by one year," Chilton says.
Susie* is a thoughtful, sensitive woman who works as a teacher in Melbourne. She never imagined she'd be "the sort of person who did controlled crying", until she began to suspect, 12 months after the birth of her daughter Poppy*, that she was suffering from postnatal depression. "A friend of ours who'd done it with her kids sat us down and had a very sane talk about the importance of the whole family's health," she recalls. "So we really committed to it.
"It took a lot longer than the books said: more like a fortnight than three nights. But the first three were by far the worst - it was totally brutal. Both my partner and I were going in and out, but after a while, going in just seemed to make her worse, so we got really tough and just let her cry till she fell asleep. One night, that took three hours." It "was very hard to stick to our guns", but within a week, Poppy was sleeping from 7.30pm to 5.30am most nights. Even now, however, six months later, "on average, we still have one night a week where we have to let her cry herself to sleep once in the night.
"The weirdest thing about it was that it actually seems to have made her more cheerful during the day," says Susie. "Part of that is probably just that she's getting more sleep. But it does seem to have made her more confident and settled. I would never have done it if I'd thought, even after one night, it was doing her any harm. You've got to stay confident and remember you're doing it out of love: love for them, and also for yourself. I just feel like this big cloud lifted from my life."
Postnatal depression is at the heart of the controlled-crying debate: if a baby doesn't sleep, neither do its parents, which is a risk factor for depression, which is terrible for everybody. One of the most famous studies about controlled crying, in fact, was conducted in Melbourne in 2006 to assess the impacts of baby sleep on maternal wellbeing. Results showed that controlled-crying-trained babies (taught "progressive settling" or "camping out" from eight months of age) did sleep slightly better than their non-trained counterparts, but by two years old, those improvements were statistically insignificant. "But the mums had significantly fewer postnatal depression symptoms: 11 per cent versus 22 per cent," explains Harriet Hiscock, who conceived the study.
In the original research, there were no measures taken to see how the babies themselves were affected by controlled crying. But in 2012, researchers published a follow-up of 70 per cent of the original subjects. This time they assessed child mental health, too, via cortisol measurements. "At six years, we found that there was absolutely no difference between the two groups, either in sleep, behaviour or parent mental health," says Hiscock.
In our family's case, and certainly without our help, our daughter's sleep has improved over time. Now, at 2 1/2, she often wakes once, briefly, in the night, and I go in to her, and I can live with that.
Indeed, some part of me knows that it's precious time. Just the two of us, alone together, there in the dark.
* Names have been changed
This is an edited version of an article which appeared in Good Weekend magazine.