THE MYSTERY. Our brain regulates our body’s functions according to an internal circadian clock. When the circadian clock is out of sync with our surroundings, sleep disorders often follow. How can we reset our body clock?
The Case of the Night Owl
The thin woman sitting in front of me was in her mid-twenties but looked older. She was haggard, the bags under her eyes were a grayish blue, her eyes were bloodshot, and she had difficulty focusing during the medical interview. I sometimes had to ask her the same question several times. She was obviously exhausted, but she told me that it was taking her three to four hours to fall asleep every night and she could not force herself to get up in time to get to work by eight. Even the several alarm clocks she used didn’t help; she slept through them. She had arranged for her mother to give her a wake-up call, but sometimes even the phone’s ringing failed to rouse her. Because of her exhaustion, her performance at the office was becoming unsatisfactory, and she felt she was at risk of losing her job.
She told me that she had first become aware of these symptoms when she was a teenager. She would stay up past midnight and many mornings her mother would have to drag her out of bed to go to school. After she got there she fell asleep in her morning classes. Consequently, she had a great deal of difficulty in school, and she barely managed to graduate because she missed so many classes and had poor grades. She was determined to go to college, but she had to take courses in the afternoons to cope with her sleepiness. I asked her whether she ever felt wide awake and alert. She answered, “Weekends. I don’t understand it.” That was the clue I needed.
Not All Body Clocks Are Set to the Same Time
In Chapter 1, I described the mechanism located in our brains that sleep scientists call the circadian clock. One of the many functions of this clock is to control what time of day we feel sleepy and what time we are alert. In some people, the clock runs late, and as a result, they tend not to become sleepy until late at night. In some people, the clock runs early, and they feel sleepy early in the evening. And in still others, the clock seems to work erratically. These differences in the circadian clock (or circadian rhythms) among the general population are not in themselves symptoms of a disease. People with differing circadian clocks can be perfectly healthy. Problems arise when people’s circadian clock is out of sync with the demands of their work or other schedules. Recent research suggests that some of these problems are the result of genetic changes in the system that controls the circadian clock since a genetic component plays a part in determining our circadian rhythms. It is also beginning to appear that abnormalities in the clock might lead to obesity and diabetes.
DELAYED SLEEP PHASE: THE NIGHT OWL
For people with delayed sleep phase (night owls), the clock seems to run three or four hours or more late. It is as though a person who lives in Boston has an internal circadian clock set to Seattle time. Such people do not feel drowsy until around one to three o’clock in the morning or sometimes later. During the week, they have tremendous difficulty getting out of bed to get to work or school, and once there they remain drowsy throughout the day, often nodding off in class or at work. Then on weekends they sleep until noon or even later and wake up feeling alert and refreshed.
Complicating the situation among teenagers is that they often participate in late-night activities involving video games, social media, and texting. It is usually a parent who drags the student with delayed sleep phase out of bed to go to school. Parents can help their children moderate their nighttime behavior so that they can get to sleep at an earlier hour. But rather than sending perpetually sleepy children to school, where they are likely to fall asleep and perform poorly, parents might also need to take their night owl to a doctor.
People who have delayed circadian rhythms frequently go to the doctor complaining of insomnia because they cannot fall asleep at a normal time. Simply put, their internal clock will not let them feel sleepy until it has decided that it is bedtime, and this is as much a physical characteristic as a person’s hair or eye color. It is neither normal nor abnormal. Though such people may feel better when they realize they don’t have a medical condition, their body clocks can nonetheless cause problems in their daily lives.
Dealing with children or family members with body clock irregularities can be problematic, especially for parents of school-age children. Getting these children through school can be a challenge as it puts stress on the routine that most parents use to keep everyone in the family on schedule.
For children with poor bedtime habits, changes in behavior can result in better sleep habits. Most important, children should limit or eliminate their late-night use of electronics. But when the child is a genuine night owl, parents might try communicating with school officials and teachers regarding their child’s physiological need to adhere to a different sleep schedule and the impact this will have on the student’s school performance. They can request that schedule adjustments be made to help the student cope. Specifically, they can request that the student be given classes that begin in the afternoon. In my experience, some school systems are accommodating to such requests while others resist them. But parents will find that if the school is willing to accommodate the child’s scheduling needs, this can be a good first step in reducing the stress on both student and family.
Probably the best long-term solution for adults with delayed sleep phase is to find a career whose work hours are in sync with their body’s schedule. Some of my patients with a delayed clock have been successful in the entertainment business and in service industries such as restaurants because the workday begins later. Today, there are many jobs for people who want to stay up late and sleep in.
Night owls can also experience relationship issues caused by their sleep pattern. Conflict may occur in couples when one partner is an early bird and the other a night owl. When 10:00 P.M. rolls around, one partner might be ready for sleep while the other is ready to rock and roll. Although we might expect night owls to find more success in relationships or marriages with other night owls, it is not always the case. As a colleague noted, “I am a night owl and married to a lark—it works really well having alone time. One daughter is a night owl, the other is a lark.”
Although our circadian clocks are to some extent part of our genetic makeup, researchers have found two approaches that can sometimes be effective in changing circadian rhythms. The first, chronotherapy, involves adjusting the sleep schedule so that the sleeper goes to bed two successive hours later every couple of days until he or she has worked his or her way around the clock. Someone whose clock says that a good time to go to bed is 2:00 A.M. will go to bed at 4:00 for two days, then at 6:00 for the following two days, and so on until a desirable bedtime is reached. (Obviously, for schoolchildren, this can only be tried during holidays.)
After the patient has moved the bedtime around the clock until a desirable bedtime is reached, she or he must then consistently choose this time to go to bed. Some sufferers have had success with this method, but they need to be careful, for if they then stay up later for one or more nights, they might fall back into their old routine.
Another treatment involves adjusting the sleeper’s exposure to light, which as we saw in Chapter 1 helps regulate the circadian clock. Teenagers, in particular, who use electronic devices at night might find that the light exposure can make it difficult for them to fall asleep, so they need to stop using electronic devices at bedtime. Computer programs and smartphone apps are also available that can adjust the light exposure of device displays.
Morning exposure to bright light from either natural sunlight or a lamp (blue light is the most effective) or even electronic screens can help people who have delayed body clocks wake up. In far northern and southern locations the sun rises late in wintertime; thus, lamps might be used in the mornings to simulate sunlight. Such lamps are used to treat seasonal affective disorder (SAD), also called winter depression, which seems to be brought on by insufficient sunlight in winter (see Chapter 16). They can also help people regulate their internal clock. For people with delayed sleep phase, however, such help might be only temporary: if they stop using the lights, they will probably fall back into the same undesirable sleep pattern. However, for night owls who need to be larks, sunlight exposure and chronotherapy are worth trying since they might offer at least short-term benefits.
Some night owls try to adjust their circadian clocks by using medication. Melatonin, a sleep-aid supplement billed as the “hormone of sleep,” was extremely popular in the 1990s in treating sleeplessness and, in particular, circadian rhythm problems. I am sometimes reluctant to recommend melatonin for reasons I will address in more detail in Chapter 20. Although it might work for some people, the long-term implications of its use in children and teenagers have not been adequately studied.
ADVANCED SLEEP PHASE: THE LARK
Opposed to the night owl is the lark: the person whose circadian clock runs early. Larks often get tired early in the evening, by 9:00 P.M. or earlier, and are unable to stay awake longer, then wake up between 4:00 and 6:00 A.M. People with advanced sleep phase might report symptoms of insomnia and complain of waking up too early and not being able to fall asleep again. For them it is like living in Seattle with an internal circadian clock set to Boston time. Such people might seek medical attention because they believe that their early morning awakenings are abnormal. Since they wake up when everyone else is asleep, it must be a sign that there is something wrong with them. But as with delayed sleep phase, advanced sleep phase is not a disease; it is a biological condition with which some people are born. The best way to cope with a circadian clock that runs early is to choose a lifestyle and career that is in sync with the clock.
People with advanced sleep phase usually do not have problems in the workplace because those with day jobs can arrive on time and stay alert all day. They are often very successful at certain jobs for which their circadian clocks represent the ideal schedule. Benjamin Franklin recommended going to bed early and getting up early. In fact, he thought sleep was a waste of time. Farmers, surgeons, anesthesiologists, and nurses frequently have the kind of schedule that suits advanced sleep phase; often they self-select into those careers. In most places of the world, the day shift for nurses begins at 7:00 A.M. and for anesthesiologists and surgeons, the drive from home to work usually occurs before dawn. They are frequently already in the operating room at 7:00. On the other hand, people with advanced sleep phase find night shift work difficult if not impossible and should avoid it.
But although larks have less trouble than night owls coping with standard work schedules, they can have serious difficulties fulfilling social obligations. They are often too sleepy to attend evening events and family get-togethers.
WHEN THERE DOESN’T SEEM TO BE A CLOCK AT ALL
Some people do not seem to become sleepy at night or they sleep at random times over the course of a twenty-four-hour day. It is believed, for example, that Leonardo da Vinci took catnaps every few hours. Parents should be aware and concerned if their teenager starts to have such a sleep pattern; one cause of these problems could be drug use (see Chapter 17). Unlike the advanced and delayed sleep phase patterns mentioned above, this is a disorder (known medically as non-24-hour sleep-wake rhythm disorder) that might require treatment.
This type of abnormal sleep pattern is sometimes seen in people who have suffered damage to the part of the nervous system that controls the circadian clock as well as in people with certain psychiatric disorders. People with certain types of blindness are unable to synchronize their body clocks and might have difficulty sleeping at night. The sleep difficulty may respond to a melatonin-type medication. Although I do not recommend melatonin for people with the owl and lark patterns, I do recommend treatment of patients who have no circadian rhythm if their sleep-wake pattern causes them distress.
AN ENTIRE COUNTRY OF NIGHT OWLS?
Some Americans visiting Spain have discovered that the entire country seems to be on a different clock from theirs. Telephone a restaurant in Spain and ask for a reservation for two at 7:30 P.M. and you are likely to hear the person at the other end suppressing a giggle. You will then politely be told that the restaurant does not open until 8:30 and the chef does not arrive until about 9:00. Restaurants in Spain are packed at midnight. Are culture and lifestyle the only explanation for this?
As we can see from the time zone map, most of Spain is west of England. Logically Spain should be either in England’s time zone or an hour behind England. However, it is not. Spain is in the Central European time zone and has the same time as France, Poland, and Germany. Why? In 1940, Generalissimo Francisco Franco, the dictator of Spain, in an act of solidarity with his ally Nazi Germany, changed Spain’s time zone to match that of Germany and therefore the rest of Europe. So on January 1, 2016, sunset was 3:31 P.M. in Chełm, Poland, and 6:13 in Malaga, Spain—a two-hour and forty-two-minute difference, even though the two cities are in the same time zone. Thus days seem to last longer in Spain than in the rest of Europe, and exposure to light keeps people from falling asleep. I am convinced that this is one of the reasons Spaniards are such night owls.
Jet Lag
One of the most common conditions affecting a person’s body clock is jet lag. Unknown until the mid-twentieth century—only in the past forty years have people become accustomed to flying very long distances in high-speed aircraft—jet lag can present sleep problems that last for days. Many people find that when they move through several time zones their body clocks become disoriented and confused. (Jet lag does not affect people who fly long distances within a time zone.) Currently, millions of people cross time zones every day. For some it is part of their job. The flight crew of a commercial aircraft is a perfect example. Most have learned to adjust to the jet lag in their daily lives, whereas an ordinary traveler still has to learn.
The impact of jet lag on a passenger’s sleep depends on whether the plane is traveling east or west and the number of time zones it crosses, although since the world has twenty-four time zones, a person who crosses twelve is affected equally whether traveling east or west.
FLYING EAST
When people fly east, they “lose” time. On a typical flight from, say, New York to Paris, the flight will take about seven hours. Since Paris time is six hours ahead of New York time, a flight that leaves around 9:30 P.M. will arrive in Paris at 10:30 A.M. When the plane takes off, the body thinks it is 9:30, and, in fact, it is 9:30. But when the plane lands seven hours later, the body thinks it is 4:30 A.M. when it is actually 10:30. Although it is midmorning, the body thinks it is the middle of the night—and you feel as if you have lost six hours. The feeling can be exacerbated by the conditions of the flight. If you are lucky, you will probably sleep for four hours. The first hour in a flight is full of commotion as passengers settle in after take off. The last hour is full of announcements as the plane prepares to land. In the middle of the flight meals are served and movies available. You need to find a way to get your body into sync with local time as quickly as possible so you can make up your lost sleep and function normally on a new schedule.
You should start your adjustments as soon as you get on the plane. Reset your watch to the local time of your destination. Get as much sleep as possible —tell the flight attendants not to offer you dinner or interrupt you for other reasons. Use an eyeshade and earplugs. Do not drink alcohol. Sleeping pills are not recommended for trips of eight hours or less because if a person takes a sleeping pill and is then awakened four to five hours later, the drug may not have worn off. The person could experience a hangover or memory loss, or become disoriented. An article published in the Journal of the American Medical Association in 1987 reported the effects of sleeping pills on three people (neuroscientists, no less!) who had flown to Europe from North America. Each took a sleeping pill and drank alcohol on the flight. Long after they had arrived, they realized that none of them had any memory of what they had seen and done for the ten hours following their landing. Many experienced travelers take melatonin as a sleep aid. (Although many experts recommend against the chronic use of melatonin, they are less concerned about its occasional use in alleviating jet lag.) One well-respected expert recommends taking 3 milligrams of melatonin at the bedtime of your destination. If you are flying from North America to Europe in the evening, for example, take the pill right before takeoff. But make sure the plane will be taking off on time! If the flight is delayed or canceled, you might find yourself in a very groggy state.
After you arrive, adapt your schedule to the schedule at your destination. If you arrive early in the morning, expose yourself to sunlight, but not until your body normally awakens, about two hours after landing (use sunglasses if necessary—this will help reset your body clock) and try to avoid taking a long nap right after you arrive. Doing so may lengthen your adjustment time. Some flight attendants have told me that when they arrive at their destination, they go for a workout even though they might be exhausted; the exercise jazzes them up for a few hours and lets them stay awake through the day and go to sleep at their normal bedtime.
FLYING WEST
Flying east to west presents a different challenge because the traveler “gains” time. A traveler on a short international flight, such as a trip from Paris to New York, would typically arrive in the afternoon, but his or her body would think that it was night. As when traveling west to east, reset your watch to the local time of your destination as soon as you get on the plane. But going east to west on a short flight, try to avoid sleeping for more than a short nap. Eat. Watch the movies. When you arrive, try to adapt your schedule to the schedule at your destination. If you arrive early in the afternoon, don’t take a long nap right away. Try to stay awake until your normal bedtime so that you can resume your normal sleep schedule.
A twelve-hour flight, such as San Francisco to Tokyo, offers different challenges. This often leaves between noon and late afternoon, and arrives in the late afternoon or evening. If you changed your watch to Tokyo time, it will seem as though you landed four hours after you took off, except that it is the next day. Your body might think it was about midnight when it was only 4:00 P.M.
With the emergence of China as an economic power, there are now many people routinely traveling to China and other countries in Asia. Experienced travelers will try to sleep on westward flights, and many will take a short-acting sleeping pill soon after boarding the aircraft. By the time they land, go through security, pick up their luggage, and get to their hotel, it is night. Usually they are exhausted enough to fall asleep at an appropriate time to wake up at their normal rising time the next morning.
DEALING WITH JET LAG NO MATTER WHICH DIRECTION YOU TRAVEL
A flight attendant offers the following tips for easing jet lag and adapting to a new time zone whichever direction you travel:
· Stay awake. If you arrive at your destination and it’s still daylight there, try to resist the temptation to nap. If you must nap, force yourself to get up before the sun sets. Splash cold water onto your face and promptly head outside for some fresh air.
· Make plans. Go out with friends—this will give you an incentive to resist cuddling back i nto that warm and inviting bed. They will be eager to see you. Don’t let them down.
· Exercise. As counterproductive as it may seem, nothing wakes up a tired body more than a good thirty to forty-five minutes of heart-pumping cardio action. If you work out during the day, when nighttime approaches, you will have a much more restful sleep.
· Drink lots of water. And I mean lots. The urge to go to the bathroom often naturally helps you stay awake.
· Eat light. But be sure to consume enough to fuel your body. Heavy meals rich in carbohydrates will make you want to sleep. Pass on the pasta, bagels, and ice cream. Eating high-fiber foods such as apples and peanut butter will give you energy and prevent constipation.
· Drink coffee. Enjoy as much as you’d like, but if you like it sweet, use a sugar substitute to avoid taking in excessive carbohydrates. Avoid coffee in the few hours before the local bedtime.
· Have fun. Do something you love. Staying awake is such a mental activity. Talk on the phone, e-mail a friend, dance, garden, cook, shop, etc. Doing activities you enjoy will distract you from your physical exhaustion.
· Avoid sedentary activities. Reading, watching TV, or knitting will most likely make you fall asleep. Stick with activities that involve your body and your mind.
From my own experience, I offer one last piece of advice: If you are traveling to an important meeting at which you must be alert and articulate, do not schedule your arrival for the day of the meeting. About twenty years ago, I attended a medical meeting in Cairns, Australia. For most of the participants, getting there was a long journey. The North Americans flew west. The Europeans flew east. Most participants traveled about twenty to thirty hours. The first meeting was held on the day most of them arrived, and the attendees were exhausted. When the first speaker started showing slides and the lights were dimmed, almost the entire audience fell asleep. Imagine a room full of sleeping sleep specialists who snapped awake when the lights came on between presentations! The following day nobody could remember any of the presentations, although they had probably been excellent. Sleep specialists should know better than to schedule their arrival for the day of the first session!
Returning home in either direction will again result in a shift of the circa-dian clock. Travelers can count on taking several days to recover from a short trip and up to a week or more to recover from a long trip. Don’t schedule anything important for several days after you return.
The Constant Traveler
Some people are constantly on the move; their work does not allow them to settle in any particular time zone for long enough to reset their body clocks to local time. A world-renowned violinist, Leonard Schreiber, described his pattern to me: “I travel constantly crisscrossing the globe and time zones and have to be able to perform at concerts often on the day that I arrive. What works for me is to never try to adjust to local time, but to sleep whenever I am sleepy. I sleep like a cat. My playing is so automatic, that I think that I sometimes play while I am asleep. After a concert I am sometimes so wound up that I can’t sleep for hours, and often go out for a bite no matter what the time.”
Back to the Night Owl
The patient had classic delayed sleep phase. Her late-running body clock kept her from feeling sleepy so she could not fall asleep until 3:00 or 4:00 in the morning. As a result, during the workweek, she felt as if she were operating in a daze. But on weekends, because she slept until 1:00 or 2:00 in the afternoon, she felt alert and refreshed. Although I explained that her problem was not due to a medical condition, she wanted to try to get herself on a “normal” schedule. The first treatment we tried was chronotherapy. She took a couple of weeks off from work, and every night she went to bed two hours later until she had worked her way around the clock and began falling asleep around midnight. She also went outside as early as she could every morning to expose herself to natural sunlight. At first this worked very well, but after a few weeks she stayed up late at a party one night and her body went back to her original sleep pattern. It was evident that the chronotherapy approach was not going to be effective in the long run.
I again reminded her that she did not have an illness. I advised her to identify with her own slower circadian rhythm just as she does with her hair color and personality. I recommended that she might have a better quality of life if she looked for a job that started in the early afternoon. She took my advice and switched careers. She has for years now successfully worked afternoons and evenings. When last I saw her she was content and married to another night owl. She had adjusted and no longer considered her circadian rhythm a problem.
An ancient link exists between sunlight and our body clocks. Irregularities in a person’s circadian rhythm can cause difficulty in falling and staying asleep. Sometimes the irregularity is caused by a body clock that is different from that of most of the population. Sometimes the problem is caused by a body clock that has been confused by travel. But people whose sleep problems are caused by their body clock are usually healthy in spite of their tiredness. They simply have to find the right method of dealing with their situation—whether changing jobs to accommodate their natural sleep schedule or using chronotherapy and sunlight exposure to control it.