Why sleep is important and what happens when you don't get enough
Sleep is essential for a person’s health and wellbeing, according to the National Sleep Foundation (NSF). Yet millions of people do not get enough sleep and many suffer from lack of sleep. For example, surveys conducted by the NSF (1999-2004) reveal that at least 40 million Americans suffer from over 70 different sleep disorders and 60 percent of adults report having sleep problems a few nights a week or more. Most of those with these problems go undiagnosed and untreated. In addition, more than 40 percent of adults experience daytime sleepiness severe enough to interfere with their daily activities at least a few days each month - with 20 percent reporting problem sleepiness a few days a week or more. Furthermore, 69 percent of children experience one or more sleep problems a few nights or more during a week.
According to psychologist and sleep expert David F. Dinges, Ph.D. of the Division of Sleep and Chronobiology and Department of Psychiatry at the University of Pennsylvania School of Medicine, irritability, moodiness and disinhibition are some of the first signs a person experiences from lack of sleep. If a sleep-deprived person doesn’t sleep after the initial signs, said Dinges, the person may then start to experience apathy, slowed speech and flattened emotional responses, impaired memory and an inability to be novel or multitask. As a person gets to the point of falling asleep, he or she will fall into micro sleeps (5-10 seconds) that cause lapses in attention, nod off while doing an activity like driving or reading and then finally experience hypnagogic hallucinations, the beginning of REM sleep. (Dinges, Sleep, Sleepiness and Performance. 1991)
Everyone’s individual sleep needs vary. In general, most healthy adults are built for 16 hours of wakefulness and need an average of eight hours of sleep a night. However, some individuals are able to function without sleepiness or drowsiness after as little as six hours of sleep. Others can't perform at their peak unless they've slept ten hours. And, contrary to common myth, the need for sleep doesn't decline with age but the ability to sleep for six to eight hours at one time may be reduced. (Van Dongen & Dinges, Principles & Practice of Sleep Medicine. 2000)
What causes sleep problems?
Groups that are at particular risk for sleep deprivation include night shift workers, physicians (average sleep = 6.5 hours a day; residents = 5 hours a day), truck drivers, parents and teenagers. (American Academy of Sleep Medicine and National Heart, Lung, and Blood Institute Working Group on Problem Sleepiness. 1997).
How environment and behavior affect a person’s sleep
Stress is the number one cause of short-term sleeping difficulties, according to sleep experts. Common triggers include school- or job-related pressures, a family or marriage problem and a serious illness or death in the family. Usually the sleep problem disappears when the stressful situation passes. However, if short-term sleep problems such as insomnia aren't managed properly from the beginning, they can persist long after the original stress has passed.
Drinking alcohol or beverages containing caffeine in the afternoon or evening, exercising close to bedtime, following an irregular morning and nighttime schedule, and working or doing other mentally intense activities right before or after getting into bed can disrupt sleep.
If you are among the 20 percent of employees in the United States who are shift workers, sleep may be particularly elusive. Shift work forces you to try to sleep when activities around you — and your own "biological rhythms" — signal you to be awake. One study shows that shift workers are two to five times more likely than employees with regular, daytime hours to fall asleep on the job.
Traveling also disrupts sleep, especially jet lag and traveling across several time zones. This can upset your biological or “circadian” rhythms.
Environmental factors such as a room that's too hot or cold, too noisy or too brightly lit can be a barrier to sound sleep. And interruptions from children or other family members can also disrupt sleep. Other influences to pay attention to are the comfort and size of your bed and the habits of your sleep partner. If you have to lie beside someone who has different sleep preferences, snores, can't fall or stay asleep, or has other sleep difficulties, it often becomes your problem too!
Having a 24/7 lifestyle can also interrupt regular sleep patterns: the global economy that includes round the clock industries working to beat the competition; widespread use of nonstop automated systems to communicate and an increase in shift work makes for sleeping at regular times difficult.
Health problems and sleep disorders
A number of physical problems can interfere with your ability to fall or stay asleep. For example, arthritis and other conditions that cause pain, backache, or discomfort can make it difficult to sleep well.
Epidemiological studies suggest self-reported sleep complaints are associated with an increased relative risk of cardiovascular morbidity and mortality. For women, pregnancy and hormonal shifts including those that cause premenstrual syndrome (PMS) or
menopause and its accompanying hot flashes can also intrude on sleep.
Finally, certain medications such as decongestants, steroids and some medicines for high blood pressure, asthma, or depression can cause sleeping difficulties as a side effect.
It is a good idea to talk to a physician or mental health provider about any sleeping problem that recurs or persists for longer than a few weeks.
According to the DSM IV, some psychiatric disorders have fatigue as a major symptom. Included are: major depressive disorder (includes postpartum blues), minor depression. dysthymia, mixed anxiety-depression, seasonal affective disorder and bipolar disorder .
Teenagers, sleep problems and drugs
According to a long-term study published in the 2004 April issue of Alcoholism: Clinical and Experimental Research. young teenagers whose preschool sleep habits were poor were more than twice as likely to use drugs, tobacco or alcohol. This finding was made by the University of Michigan Health System as part of a family health study that followed 257 boys and their parents for 10 years. The study found a significant connection between sleep problems in children and later drug use, even when other issues such as depression, aggression, attention problems and parental alcoholism were taken into account. Long-term data on girls isn't available yet. The researchers suggest that early sleep problems may be a "marker" for predicting later risk of early adolescent substance abuse — and that there may be a common biological factor underlying both traits. Although the relationship between sleep problems and the abuse of alcohol in adults is well known, this is the first study to look at the issue in children.
Nightmares are dreams with vivid and disturbing content. They are common in children during REM sleep. They usually involve an immediate awakening and good recall of the dream content.
Sleep terrors are often described as extreme nightmares. Like nightmares, they most often occur during childhood, however they typically take place during non-REM (NREM) sleep. Characteristics of a sleep terror include arousal, agitation, large pupils, sweating, and increased blood pressure. The child appears terrified, screams and is usually inconsolable for several minutes, after which he or she relaxes and returns to sleep. Sleep terrors usually take place early in the night and may be combined with sleepwalking. The child typically does not remember or has only a vague memory of the terrifying events.
Sleepiness and decision making
In the August 2004 issue of the journal Sleep. Dr. Timothy Roehrs, the Director of research at the Sleep Disorders and Research Center at Henry Ford Hospital in Detroit published one of the first studies to measure the effect of sleepiness on decision making and risk taking. He found that sleepiness does take a toll on effective decision making.
Cited in the October 12, New York Times Science section, Dr. Roehrs and his colleagues paid sleepy and fully alert subjects to complete a series of computer tasks. At random times, they were given a choice to take their money and stop. Or they could forge ahead with the potential of either earning more money or losing it all if their work was not completed within an unknown remainder of time.
Dr. Roehrs found that the alert people were very sensitive to the amount of work they needed to do to finish the tasks and understood the risk of losing their money if they didn't. But the sleepy subjects chose to quit the tasks prematurely or they risked losing everything by trying to finish the task for more money even when it was 100 percent likely that they would be unable to finish, said Dr. Roehrs.
Consequences of lost sleep
According to the National Commission on Sleep Disorders Research (1998) and reports from the National Highway Safety Administration (NHSA)(2002), high-profile accidents can partly be attributed to people suffering from a severe lack of sleep.
Each year the cost of sleep disorders, sleep deprivation and sleepiness, according to the NCSDR, is estimated to be $15.9 million in direct costs and $50 to $100 billion a year in indirect and related costs. And according to the NHSA, falling asleep while driving is responsible for at least 100,000 crashes, 71,000 injuries and 1,550 deaths each year in the United States. Young people in their teens and twenties, who are particularly susceptible to the effects of chronic sleep loss, are involved in more than half of the fall-asleep crashes on the nation's highways each year. Sleep loss also interferes with the learning of young people in our nation's schools, with 60 percent of grade school and high school children reporting that they are tired during the daytime and 15 percent of them admitting to falling asleep in class.
According to the Department of Transportation (DOT), one to four percent of all highway crashes are due to sleepiness, especially in rural areas and four percent of these crashes are fatal.
Risk factors for drowsy driving crashes:
Late night/early morning driving
Patients with untreated excessive sleepiness
People who obtain six or fewer hours of sleep per daySource: www.apa.org