Media Coverage

Dr. David Joffe - The Mysteries of Sleep Occupy His Waking Hours

1 Jul 2000

"Most people come to me with sleep apnoea and insomnia but I see everything from snoring to sleep-walking, sleep-talking, sleep-jumping in and out of cupboards, and sleep-epilepsy. I have what we call ‘1:28 patients’ and "3:34 patients’ - people who wake up on the dot at the same time every night. One of the weirdest behaviors is sleep-eating. People gorge themselves - sometimes they know they've done it, more often they don't, they just wake up feeling full.

People with apnoea, who choke and wake at night, are up to 12 times more likely to have driving accidents, and not necessarily because they're tired. More likely it's because they have problems with attention, concentration and judging distances. Not sleeping is a killer; sleep deprivation has been the cause of major accidents around the world. Sleep is a health and safety issue and it's crucial that we understand it better. As a sleep physician, the eight hours of sleep are more fascinating to me than anything else.

Sleep is a drive, like hunger. It's an overwhelming urge allowing the body to rest and the brain to recharge. By the time people come to me they've usually had a history of sleep disturbance that goes back at least three years. It's a chronic, debilitating illness and those who suffer from it don't just get more tired. It affects everything.

When I'm studying someone I'll bring them into [Sydney's] Royal North Shore Hospital's sleep clinic overnight so we can watch them properly. We attach sensors to them and monitor everything from brain activity to body position, how good their nasal flow is, muscle activity in their chin, and their eye movements to see whether they're in dream sleep. We may look at abdominal movements and whether their legs are kicking and twitching as part of ‘restless leg syndrome’. We'll tape them on an infra-red camera.

When I started working in this area 11 years ago, it was very much in its infancy. We know more now and we're starting to see specific links between the lack of different kinds of sleep and certain waking problems. Deprive people of recuperative sleep and they'll be very tired the next day, for example. But deprive people of dream sleep and they won't be tired, they'll be damned irritable. There is convincing evidence to tie insomnia with depression.

Looking at the animal kingdom triggers even more questions. Dolphins and whales can ‘sleep’ one side of their brain while the other looks out for predators and ensures they don't drown. Then they ‘sleep’ the other. We know why they do it; we have no idea how. Blind people are fascinating. With sighted people, sunlight hitting the brain via the optic nerve suppresses sleep hormones. If you're blind you don't have that cue so you have to set your circadian rhythms in other ways - TV, radio, or other cues. I work with Vietnam veterans who sometimes have very vivid and unpleasant dream recall running in their heads like a tape loop.

Dreams in general are an uncracked mystery. They come as part of the night's cycle of sleep and while we can follow the architecture of sleep from deep sleep to REM [Rapid Eye Movement] and back, we don't know why our minds work as they do. My own theory about dream sleep is that it's when the brain files away all the little bits of memory - that's why people wake up having weird dreams about a conversation they had yesterday in a car they owned 10 years ago in a place they hadn't visited for two decades.

Some Freudians argue that you become paralysed during dream sleep to protect yourself from violence in your dreams and that dreaming is about releasing the violent or sexual fantasies that keep you sane. If you deprive people of dream sleep, they say, they become psychotic. That's not the case. They just become grumpy. We know the body becomes paralysed in dream sleep. There's even a specific disorder where individuals, usually men over 50, don't get dream paralysis and they will have violent outbursts where they start acting out what is going on in their heads.

We've come a long way in the last 15 years. We will unravel these puzzles, largely because we're developing computers powerful enough to help us look at our brains' operations, but there is no question that we're at the beginning of a new era of discovery. People ask me if I sleep okay and the answer is no. How can I? I'm an on-call physician with two small children. But I know we're right at the beginning of a very long journey and I want to be there every step of the way."

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