Chapter 8

Mixing Up Day for Night: Circadian Rhythm Disorders

In This Chapter

Defining circadian rhythm disorders

Traveling with jet lag

Working the night shift

Dealing with delayed sleep-phase syndrome (DSPS)

Looking at less common circadian rhythm disorders

You may be one of those blessed souls who never, ever has a problem sleeping — that is, until you take an extended trip that carries you across several time zones and you get hit with jet lag. Or maybe your boss switched you to the night shift, and now you find yourself solving problems, answering questions, making decisions, and having to concentrate when all you really want to do is lie down on your desk or the assembly line and take a nice long snooze.

When your job, travel, a family emergency, natural disaster, or some other reason keeps you from sleeping at night, your brain’s internal clocks can get thrown out of kilter. If you’re trying to sleep when your internal clock’s alarm keeps trying to awaken you, you can keep hitting the snooze button, but the alarm keeps ringing.

Similarly, if you must remain awake when your brain’s clock is telling you to sleep, you can end up dragging yourself through life like some creature out of a bad horror movie, and you’ll be just as scary.

Jet lag and shift-work sleep disorder are just two kinds of circadian rhythm disorders that can cause problems with sleep. Circadian rhythm disorders are classified as dyssomnias, or sleep disorders that cause problems in falling asleep or staying asleep, and also cause extreme daytime sleepiness. Translated literally, dyssomnia means “difficult sleep.”

In this chapter, we look at circadian rhythm disorders, explain what they are and what causes them, and tell you how they’re diagnosed and treated. We also offer some savvy tips for travelers and shift workers to help them ease their bodies (and brains) into the transitions caused by disrupted sleep patterns without losing too much shuteye.

Understanding Circadian Rhythm Disorders

Everyone has a 24-hour internal clock powered by his or her own individual circadian rhythm, which tells the body when to initiate important biological activities like waking, sleeping, and some hormone production. In addition, circadian rhythms help to moderate body temperature, glucose levels, and blood pressure.

In much the same way that two people may synchronize their watches to make sure they arrive some place at the exact same time, circadian rhythm uses day and night (light and dark) to synchronize your periods of sleep and wakefulness, along with other activities.

Circadian rhythm is one type of biological rhythm. Biological rhythms govern many complex activities like fertility cycles, bears’ hibernation phases, and bird and butterfly migrations. The study of body clocks and circadian rhythms is known as chronobiology.

Humans are diurnal mammals, which means in addition to being warm blooded, human brains are programmed for daylight activity and nighttime sleep. And you can’t get away from your biology, no matter how hard you may try.

Circadian rhythm disorders have become more prevalent in today’s non-stop, around-the-clock working world. Before electricity, almost everyone went to sleep at nighttime. Going to bed wasn’t so much a matter of choice as of necessity; most people couldn’t afford to burn candles or lamps for extended periods of time every night. As a result, the human sleep-wake cycle was more attuned to the rhythms of nature. When night fell, people slept. When the sun rose, people woke up.

Setting its own alarm clock: Your brain at work

You may be curious to know how your brain does such a precise job of timing its various activities. Actually, the trick is that it resets itself daily as needed. Scientists believe the environment’s light-dark cycles reset your clock, making adjustments for seasonal differences and even for sudden misalignments caused by traveling across several time zones.

Light enters the brain through the eyes and travels along a pathway to a tiny cluster of nerves in the hypothalamus, located near the brain’s center. These nerves comprise the brain’s master clock, known as the suprachiasmatic nucleus or SCN.

In the morning, when the sun rises, the SCN, reacting to the light cue, resets your internal clock. In the evening, when it becomes dark, another structure deep within the brain, the pineal gland, responds by releasing the hormone melatonin. Bright light can suppress melatonin. Researchers believe that melatonin serves as a trigger, telling your brain it’s dark outside and therefore time to sleep. By contrast, in nocturnal animals, the rise in melatonin signals the brain to awaken.

Your brain uses the light that comes in through your eyes to reset your circadian rhythms each day, so you’re always in sync with your environment. But the changes you encounter when you cross several time zones in a matter of hours are too big for your brain to compensate for adequately in one day, which is why you usually need two or three days to overcome the effects of jet lag.

Blind people often have circadian rhythm disorders and insomnia. If their blindness includes lesions in the nerve pathway between the eye and SCN, severe problems result. They can reset their internal clocks with melatonin, but it should be done under a doctor’s supervision to determine the size and timing of the doses, as well as the duration of the treatment.

With today’s artificial lighting, around-the-clock shift work, 24-hour grocery stores, late-night clubs, and 2 4/7 Internet, people push themselves for days without ever entering the comforting embrace of the dark. But the human brain didn’t evolve to operate that way. Many people have developed some modern sleep maladies resulting from the disruption of their circadian rhythms. When your circadian rhythms are disturbed, you’re thrown out of sync.

Circadian rhythm disorders disrupt how and when sleep occurs during a 24-hour period. When something happens to disrupt your circadian rhythms, your natural sleep-wake cycles are thrown out of whack, and sleeplessness may result.

Researchers recognize six circadian rhythm disorders:

Time zone–change syndrome, also known as jet lag

Shift-work sleep disorder

Irregular sleep-wake pattern

Delayed sleep-phase syndrome (DSPS)

Advanced sleep-phase syndrome (ASPS)

Non-24-hour sleep-wake syndrome

In the following sections, we discuss each disorder individually.

Leaving on a Jet Plane: Jet Lag

You’re on the vacation of a lifetime, a whirlwind seven-day European tour of five cities. But the first three days, you feel like a train wreck, and you can barely drag yourself out of bed, much less pay attention when the tour guide shows you where Romeo proposed to Juliet. You’re more interested in finding out where Shakespeare slept and whether or not it still has a soft bed that you can snooze in for a few hours, or maybe even days.

What’s going on? You have a classic case of jet lag.

Jet lag is a circadian rhythm disorder that occurs when you cross many time zones in rapid succession, so fast in fact that that your brain’s circadian rhythm is no longer synchronized with your local time. Your clock gets thrown out of whack and boy, do you feel it!

How does jet lag affect you?

Some people are more susceptible to jet lag than others. The primary symptom of jet lag is extreme fatigue. In fact, you may be so sleepy that you almost feel sick. You may also experience the following:

Anxiety

Cardiac arrhythmias (on rare occasion)

Confusion

Digestive upsets that may include constipation, diarrhea, or a combination of both

Headache

Insomnia

Irritability

Lowered immunity to illness

Memory loss

Nausea

Poor muscular coordination

Profuse sweating

These symptoms aren’t exactly the sort of companion you want along on your dream trip. The good news is that jet lag is self-limiting and doesn’t have any long-term detrimental effects. The bad news is that while you have it, you feel so lousy that it may spoil your trip, or diminish your effectiveness if you’re on a business trip and expected to be sharp.

Travelers flying north and south don’t experience jet lag because they don’t cross any time zones. Travelers flying east experience the worst jet lag because they lose an hour out of their schedule for every time zone they cross. Travelers flying west do suffer from jet lag, but because they gain an hour for every time zone they cross, adjusting to the time difference is usually easier for them than for travelers flying east.

Under normal circumstances, the brain can adjust its internal clock by an hour or two each day. To calculate how long you need to recover from jet lag, determine how many time zones you’ve crossed. For example, if you’ve crossed six time zones (like you do when you fly across the Atlantic Ocean), you need anywhere from three to six days to spontaneously recover from the effects of jet lag.

It can take your internal clock several days to adjust to the new local time, which may cause you problems with getting to sleep and waking up at the right time in your destination city, along with some of the other symptoms we mention earlier in this section.

If you just cross one or two time zones, the effects may be so insignificant you don’t really notice them. However, if you cross three or four time zones, you will almost assuredly feel the effects of jet lag.

Why does traveling across multiple time zones cause jet lag?

Earth is divided into 24 different time zones, one for each hour of the day. Each time zone runs from the North to the South poles and is approximately 1,000 miles across at its widest point at the Equator. The United States has six time zones: Eastern, Central, Mountain, Pacific, Alaska, and Hawaii-Aleutian Time.

Time progresses in a clockwise fashion through the time zones, so when it’s 11 a.m. in the Eastern time zone and folks are thinking of lunch, people in the Central time zone are thinking of their 10 a.m. coffee break, people in the Mountain time zone are arriving at work at 9 a.m., and commuters in the Pacific time zone are just starting their morning trip to work at 8 a.m. Meanwhile, the hardy souls in Alaska are eating breakfast at 7 a.m., and Hawaii’s residents are still asleep at 6 a.m.

When you cross several time zones, your brain continues to operate according to the light-dark cycle programmed into your brain by your circadian rhythm “clock” in your place of origin. If you leave New York City at 6 p.m. on a dinner flight to London, when you arrive seven hours later, your brain thinks it’s 1 a.m. In reality, because England is seven hours ahead of your home time zone, it’s 8 a.m. London time, probably with a full day of scheduled activities ahead of you. Your body feels like you pulled an all-nighter. The more time zones you cross, the greater the likelihood that you experience jet lag symptoms.

Preventing jet lag

We don’t know of a 100-percent effective way to prevent jet lag when you’re traveling across multiple time zones; however, you can take steps before you travel to minimize its effects. These preventive measures include

Adjust your bedtime. Some people swear that adjusting their bedtimes before traveling keeps the worst symptoms of jet lag at bay. Before leaving on a trip, adjust your bedtime by an hour each night to compensate for the time change. For example, if you’re flying from Los Angeles to New York City, your body clock loses about three hours, so three nights before you leave, go to bed an hour earlier than normal. Two nights before you leave, go to bed two hours earlier. The night before you leave, go to bed three hours earlier. Be sure to keep the total number of hours you sleep the same. For example, if you normally sleep seven hours, don’t sleep for six hours or eight hours just because you adjusted your bedtime, because that defeats the purpose of changing your bedtime.

Keep up your exercise. Some studies have found that travelers who exercise regularly suffer less intense jet lag symptoms than their more sedentary counterparts, perhaps because regular exercise keeps your metabolism functioning more smoothly. If you have scheduled an upcoming trip across several time zones, try walking briskly for at least 20 minutes a day in the two weeks prior to your departure. Keep up your activity while traveling. Try walking during layovers or even down your plane’s aisles if space permits.

Manage your stress: Just as some people with insomnia worsen their sleeplessness by thinking about it too much, you can intensify your jet lag by worrying about it, or by worrying about things back home. Try to have all your affairs in order before you leave on your trip; consider asking your doctor for an antianxiety medication if your stress seems unmanageable.

If you’re tired or have missed a lot of sleep before you begin your trip, you’re putting yourself at a disadvantage (unless you sleep for a long time on the plane and arrive at a destination where it’s morning). Travelers who start out tired are much more likely to experience severe symptoms of jet lag than those travelers who are well rested before their trip.

Move your watch forward. Set your watch to the time zone of your destination while you’re still on the plane. If you travel often, you may find purchasing a watch that shows two times zones helpful. When you arrive at your destination, step right into the pattern of activity there. Don’t give in to the desire to nap or sleep because that only stretches out the time it takes for your body to adjust to the new time zone. If you absolutely must nap, make it short (15 to 30 minutes) so that it doesn’t ruin your sleep later.

Although you want to avoid caffeine while traveling, after you reach your destination, drinking a caffeinated beverage can give you the burst of energy you need to make it through the day. By the time evening rolls around in your destination city, you can fall into bed and sleep soundly. However, your circadian alarm may begin ringing, and you find yourself waking repeatedly because it’s not “night” where you began your journey. Many people find that a sleeping pill can help.

Stay properly hydrated. Drink plenty of water before and during your trip. Some studies have suggested that dehydration may be responsible for some of jet lag’s symptoms. Dehydration puts enormous stress on the entire body. Dehydrated passengers on trans-Atlantic flights are known to suffer a higher risk of pulmonary blood clots.

Avoid drinking either alcohol or coffee while traveling because both can act as diuretics, a chemical that forces water out of your body and contributes to dehydration.

Take timed melatonin supplements. The jury is still out about whether or not melatonin produces any real benefit for people trying to prevent jet lag. Some people swear by it; others say it has no benefit at all. Melatonin supplements can reset your brain’s clock and fool the brain into thinking it’s nighttime (which should prepare a person for sleep). Theoretically, you may abate the effects of jet lag by taking melatonin at carefully timed intervals. However, don’t use melatonin in children, particularly those kids with a history of seizure disorders, because research has shown that melatonin increases the frequency of seizures.

If you want to try melatonin for jet lag, review your trip plans with your doctor and ask him to suggest the appropriate doses and timing. His suggestions will depend upon your travel destination and how many time zones you’re crossing.

In general, you want to take melatonin at the time you want your brain to think it’s late evening. When traveling from west to east, take melatonin in the early evening to push up the period of peak nighttime melatonin in the brain and make yourself feel sleepy earlier than you normally do. If you’re traveling from east to west, take supplemental melatonin in the morning to extend sleep.

Don’t take organic melatonin. You want completely synthetic melatonin. Because melatonin is a food supplement, it doesn’t have many of the rigorous quality controls that are required for pharmaceuticals. You can purchase melatonin at any grocery, health food, or discount store.

Try bright-light therapy. Bright-light therapy exposes people preparing to travel to special bright lights for several hours. You use the lights near the time you want to wake up in your destination to manipulate your biological clock. This exposure resets your brain’s master clock (known as the suprachiasmatic nucleus or SCN) and helps you adjust to the new time zone with fewer debilitating symptoms of jet lag.

Since the discovery of bright-light therapy as an effective preventive treatment for jet lag, many companies have developed light products that allow consumers to use the technique in the comfort of their homes or hotel rooms at their destination. But most of these lights are bulky, and sometimes expensive. You can now purchase relatively inexpensive gadgets like the Jet Lag Light Visor (by Bio-Brite, Inc.) that travelers can use anywhere to reset their SCN, including right on an airplane prior to arrival at their destination. For more information about purchasing light products, see the Appendix.

Watch your diet. Remember that high-carbohydrate meals make you feel sleepy, and so do foods, such as turkey, baked potatoes with the skin, and walnuts, which contain the amino acid L-tryptophan. High- protein meals make you feel more energetic and awake. Avoid salty foods, because they may make you feel bloated, and fatty foods, because they can make you feel sluggish.

Some travelers claim success in reducing the effects of jet lag by following the Argonne Diet, developed at the government’s Argonne National Laboratory in Argonne, Ill., to help soldiers overcome the effects of jet lag. For a free, wallet-size card that details the plan, contact jessiemchenry@anl.gov.

Catching a respiratory illness when traveling

An added benefit of keeping your body properly hydrated is that you lower the chance of picking up one of those nasty “airplane” respiratory infections. How come? Dry membranes in your nose, mouth, and throat are more susceptible to attack by bacteria and viruses than membranes that are moist.

Treating jet lag

If you have a choice, preventing jet lag using some of the tips in the previous section is more effective than trying to treat it. Truly effective treatments just aren’t widely available, but you can try the following tips to help yourself feel better:

Pills and supplements: Some experts contend that taking sleeping pills isn’t a good idea while you’re traveling. If you happen to be involved in an accident or find yourself in an emergency situation, your judgment and reflexes may not be as sharp if you’re under the influence of a sedative-hypnotic drug. However, your doctor may prescribe a short-acting sleep medication to help you adjust to a new schedule and sleep more soundly after you reach your destination.

Look before you buy and ask questions. Some of the jet lag formulas available over the Internet contain ingredients of dubious value. Some may cause allergic reactions in sensitive individuals, or even be dangerous for certain people. Remember, just because something is “natural” doesn’t mean it’s safe.

Customized diets and schedules: If you really want to get high-tech, you can get computer-generated sleeping and eating schedules tailored to your specific trip that claim to greatly minimize jet lag symptoms.

Visit stopjetlag.com for a personalized plan to prevent jet lag. The cost is $25 per plan. You provide your flight times and destinations, fill in some personal preferences, and the Web site sends you a computer-generated report with an hour-by-hour itinerary to help you reset your body’s clock to the time zone prevailing in your destination city. The company claims its program completely eliminates jet lag and has some impressive testimonials and reviews on its Web site to support its contentions.

Circadian suites: Some upscale overseas hotels now offer their tired, jet-lagged patrons deluxe circadian suites, complete with blackout curtains, full-spectrum artificial lighting, and 24-hour-a-day meal service to accommodate schedules that are topsy-turvy. They also offer massages and hydrotherapy to help overcome jet lag. And yes, these services are expensive, but if your company wants you on your toes to negotiate a multimillion dollar deal, you’d better believe they’re worth every penny.

Sunlight: When you arrive at your destination and start to feel the effects of jet lag, go out into the bright sunlight for at least an hour. That exposure signals your SCN to reset its internal clock.

When you return home after your trip, you may suffer from jet lag all over again. As we mention earlier, the effects of jet lag are worse for most people when traveling from west to east, so if the first leg of your trip was in that direction, the worst is behind you.

Boosting your immune system before you travel

Any way you look at it, travel is rough on the body. You leave your familiar and comforting routines and surroundings. Furthermore, you’re under moderate to extreme stress to make sure you’ve covered everything while you’re gone: kids and spouse cared for, pets boarded, bills paid, house secure, cash or traveler’s checks in hand. Then you have to pack, get to the airport on time, find a parking space, go through security, fly in a crowded plane (usually with at least one screaming baby and an intoxicated person), figure out where to go after you reach your destination and how to get there, and fight jet lag. No wonder so many travelers get sick. (Some surveys say as many as 50 to 63 percent of travelers become ill during their trips!)

You can boost your immune system before you travel and reduce your risk of picking up an opportunistic infection by taking the antioxidant vitamins A, C, and E, and also one of the herbal immune system boosters. Many herbalists prefer astragalus over the more widely known echinacea because you can take it for longer periods of time with no ill effects. Consult your doctor or local healthcare store for appropriate dosage recommendations.

If your trip’s first leg went from east to west, you may have experienced mild symptoms of jet lag, especially if you like to stay up late and sleep in. However, after your return trip, jet lag may hit you full force, especially if you’re fatigued and off your usual schedule due to your business trip or vacation. (Larks or people who like getting up at 4 to 5 a.m. may not suffer as badly.)

If time permits, leave an extra day or two at the end of your trip to recuperate at home. Trying to head straight back to work when you’re full in the throes of jet lag isn’t a good idea.

The ideas we suggest in “Preventing jet lag” and “Treating jet lag” are just as beneficial for return trips as they are for the first leg, so try to incorporate at least a few of them into your trip planning.

Working Odd Hours: Shift-Work Sleep Disorder

Some people blame Henry Ford as the father of shift-work sleep disorder, because his assembly lines made it economically feasible for factories to run all night. But that’s not exactly correct. Actually, mining operations at the dawn of the Industrial Revolution sired shift work long before automobile manufacturing was organized into assembly lines.

But the history of night work goes back even further. Night shifts date back to at least the early days of seafaring. When sailing in open seas, someone had to stand watch at the helm, regardless of the time of day or night. But as any employee who’s ever been on the night shift will tell you, bonus pay aside, working the night shift takes a big toll because working at night and sleeping during the day is contrary to human biology.

Even worse is when you work rotating or flexible shifts, meaning one week you’re on the night shift, the next week a split shift, the week thereafter a day shift, and then back to the night shift. When flex shifts were first introduced, the idea was to spread the responsibility of working the dreaded night shifts around the labor pool. But, in reality, what happens is the entire workforce is more sleep deprived, cranky, inattentive, and unable to perform up to standards. When a person’s biological clock becomes confused by the constant changes in the sleep-wake cycle, he or she hardly knows what end is up. As a result, absenteeism also rises.

When work schedules are incompatible with non-work sleep-wake cycles, shift-work sleep disorder can result. Shift workers make up 22 percent of the United States workforce, which means that at any given time, as many as 20 million sleep-deprived people are manning some of our most important jobs in law enforcement, firefighting, healthcare, power generation (including nuclear), manufacturing, broadcasting, and transportation (buses, trucks, trains, boats, and planes).

If you or one of your family members works the night shift, read on for advice and information about how to deal with sleep disturbances that can result from shift work.

Factories go all night — why can’t you?

When you’re still young, ten-feet tall, and bulletproof, you may think of sleep as optional. You hardly give a second thought to going to work or class after an all-nighter of studying or partying.

When you enter the workforce, you may carry the misconception that you can sleep any time you want and work any time you want. As a matter of fact, because young adult men are most likely to have delayed sleep-phase syndrome (see “Coping with Delayed Sleep-Phase Syndrome” later in this chapter), they’re also the most likely to seek night-shift employment because it suits their individual pattern of sleep and wakefulness.

But the human body (or brain) isn’t designed to run 24 hours a day like a factory. People need regular periods of restorative sleep to remain healthy and functioning at optimal capacity. Night-shift workers may face a whole host of problems and prejudices in a world that runs on a daytime clock.

Lacking sleep: Night-shift workers and accidents

Sleep deprivation is continually implicated in major industrial and transportation industry accidents, which includes the nuclear reactor accidents at Three-Mile Island and Chernobyl, the Exxon Valdez oil spill disaster, and the Challenger space shuttle disaster.

Employees who are sleep deprived don’t exercise the sharpness and judgment that employees who are well rested display. In emergency situations, sleepy workers may show poor judgment that exacerbates a situation.

A 1994 study placed the cost of accidents caused by disturbed sleep at $50 billion per year in the United States alone. A 1992 study showed that night-shift workers reporting difficulties sleeping have a significantly higher risk of having a fatal on-the-job accident.

Connecting sleep problems and night-shift workers

Night-shift workers are required to be alert and perform optimally at a time when their brains are telling their bodies to sleep. Then, during the day, when they really need to sleep, light, noise, family, and social obligations may keep them from getting the rest they need. And even when their bedroom has black-out curtains, sound insulation, and family and friends are kept at bay, some people still can’t sleep well because their circadian alarm continually wakes them up.

Sometimes, night-shift workers find themselves in a no-win situation — required by their bosses to be attentive and productive all night, and required by their other halves and families to be attentive and supportive all day. No wonder that many shift workers start to show signs of sleep deprivation after just a few weeks on the job. When can they sleep?

How does shift-work sleep disorder affect you?

Today’s culture celebrates the early riser; society attributes all sorts of positive personality and character traits to people who get up with the sun. Conversely, society tars night owls with an uncomplimentary brush, characterizing late risers as lazy or lacking in ambition, never mind that they worked all night long. People who work night shifts have to deal with all these negative societal assumptions at the same time they’re trying to keep their weary bodies on some semblance of a schedule and hold down their jobs.

Sleepiness isn’t the only problem night-shift workers may experience. They may also suffer from the cumulative effects of sleep deprivation, which can interfere with job performance and lead to a higher incidence of on-the-job accidents. In addition, they’re at increased risk for gastrointestinal problems, cardiovascular disease, weight gain, chronic sleep disorders, and substance abuse.

The symptoms of shift-work sleep disorder may include

Difficulty in concentrating on the task at hand

Excessive daytime sleepiness

Headaches

Insomnia

Moodiness, irritability

Poor job performance

Treating shift-work sleep disorder

The best treatment for shift-work sleep disorder is to switch to a day shift and give your brain and body two weeks or more to recover and adjust. This solution, however, isn’t often practical or possible. If you must work odd hours, follow these tips to prevent shift-work sleep disorder:

Whenever possible, avoid shifting back and forth between day-shift and night-shift schedules.

Stick to your shift schedule even on your days off.

Take special care to make your bedroom as dark as possible. Any light or noise that intrude into the room where you sleep during the day can further disrupt your sleep-wake schedule. If you do have to go outside, wear the darkest sunglasses you can find to avoid resetting your SCN.

Ask your supervisor to install bright lights at your workstation. Exposure to this bright light, especially during the first half of your work shift, can help you remain awake at night and fall asleep more quickly when you go home after your shift.

While your brain and body are becoming accustomed to your new night-shift schedule, try sleeping more than you normally do. Napping may be helpful to keep up the total quality and quantity of your sleep during this adjustment. Allow about two weeks for your brain to make the change to your new schedule.

Coping with Delayed Sleep-Phase Syndrome

Also known as phase lag syndrome, delayed sleep-phase syndrome (DSPS) is a persistent sleep disorder that results when a person’s internal biological clock is out of sync with and running behind time in the external environment. For example, a person with DSPS may not start to feel sleepy until 1 or 2 a.m. when everyone else in his household has been asleep for hours. In severe cases, someone suffering from DSPS may not become sleepy until it’s almost dawn. He has no compelling reason to stay up all night, but because his sleep phase is delayed, he doesn’t feel sleepy at the normal time of 9 or 10 p.m. like most people do. In clinical settings, DSPS is the most common circadian rhythm disorder, accounting for 40 percent of all cases involving difficulty in sleep-wake patterns.

Recent studies have suggested that DSPS can begin with behavior that desynchronizes the internal and environmental clocks. In other cases, the defect may be with the clock itself. In DSPS resulting from behavior, people who stay up a little later night after night eventually train themselves to have a delayed sleep phase, which becomes normal for them. As long as they don’t have any external demands on their schedule, they don’t see a problem.

Unfortunately, most people don’t live in a world that accommodates sleepyheads who want to snooze until noon. Classes start as early as 7:15 a.m. at many high schools and by 8 a.m. at most colleges and universities. Most jobs require you to put in an appearance by 8 or 9 a.m. at the latest, and many jobs in manufacturing, construction, or healthcare require a 5, 6, or 7 a.m. start.

If your high school student suddenly has to get up at 6:30 a.m. and get ready for school, after progressive sleep-phase delay all during summer vacation, he’s going to be in big trouble. Don’t be surprised if the school principal starts calling to tell you your son is sleeping through class or late every morning. People with DSPS may flunk out of school because they miss so many early morning classes, or lose job after job because of habitual tardiness.

DSPS is particularly prevalent among young adult males, which makes some researchers believe that at least in some cases, there may be a link between DSPS and behavioral choices, such as partying all night. An estimated 7 percent of teenagers suffer from the problem. The problem generally shows up during adolescence and, without treatment, persists long into adulthood.

Many artists, writers, and musicians have DSPS without even realizing it. They tell themselves that they can concentrate and be more productive when the rest of the world is quiet and sleeping, unaware that their inability to get to sleep at a more normal hour may be the result of an underlying disconnect between their biological clock and the world outside their window.

If delayed sleep-phase patients are allowed to sleep according to their natural rhythms, they generally sleep until late morning or early afternoon and awake feeling refreshed and alert, able to function normally.

DSPS can also be a problem for people who have suffered severe head trauma that has damaged the part of the brain that sets the internal clock. Serious illness sometimes also negatively impacts the sleep phase because sick people may have so much trouble getting to sleep that their sleep time gradually gets pushed back.

How does DSPS affect you?

If you have delayed sleep-phase syndrome, your brain doesn’t respond to the usual environmental signals for sleepiness, like the onset of darkness. In DSPS, the patient

Can’t fall asleep at the desired time

Has a “normal” bedtime of 1 or 2 a.m. or later

Sleeps normally once asleep and has few or no awakenings

Can’t wake up at the desired time

Has shorter sleep periods during the school or work week with much longer sleep periods on weekends, often with a midday or late afternoon wake time

May complain of excessive sleepiness or sleep-onset insomnia (See Chapter 4 for more information about sleep onset insomnia.)

May also complain of depression

Not surprisingly, many people call these folks “night owls.” They’re up when most people are sleeping, and sleeping when most are awake.

People with DSPS end up being out of phase with the world in which they must live, which can lead to an enormous amount of frustration and, eventually, severe sleep deprivation as they work to conform their schedules to the requirements of the working world. When DSPS interferes with a person’s ability to follow a normal schedule, he may become depressed, stressed, and anxious about not being able to fall asleep earlier. These patients can then develop sleep-onset insomnia (see Chapter 4). They become progressively sleep deprived and may succumb to the temptations of using drugs or alcohol to force sleep. If you can’t get to sleep before midnight or later, and ideally want to sleep until 10 a.m. or later, see your doctor. You may have DSPS.

Treating DSPS

DSPS can be treated effectively with light therapy. Increasing exposure to bright morning light and limiting exposure to light in the evening are sometimes all that’s needed to correct the problem. If this therapy doesn’t work, your doctor may suggest exposure to bright-light therapy in the morning using a light box. (For more information on light boxes, see the Appendix.)

If your lifestyle accommodates your delayed sleep patterns, you may not experience any negative symptoms at all, and you don’t need to seek treatment.

Another therapy that may prove useful is chronotherapy, which successively delays sleep in two- or three-hour increments daily until patients’ sleeping and waking patterns are more normal. For example, if you normally fall asleep at 4 a.m., your doctor will ask you to stay awake until 6 or 7 a.m. the first night, 8 or 9 a.m. the second night and so on until your bedtime has been adjusted to 9 or 10 p.m. Chronotherapy is fairly complex, so make sure an experienced practitioner monitors it to make sure it’s effective.

As with other circadian rhythm disorders, DSPS patients benefit from sleep hygiene education. See Chapter 6 for more information on incorporating good sleep hygiene into your bedtime routine.

Sedative-hypnotic therapy with short-acting prescription medicines can also be helpful to resynchronize the sleep cycle. Patients under a doctor’s supervision can usually accomplish this therapy with time-limited dosing because after the patient establishes the new sleep-wake cycle sleep is normalized.

Reviewing the Less Common Circadian Rhythm Disorders

Jet lag and shift work are fairly common circadian rhythm disorders, but there are three other less common conditions that fall under this same classification: irregular sleep-wake pattern, advanced sleep-phase syndrome, and non-24 hour sleep/wake syndrome. You can help prevent these disorders by maintaining a regular bedtime and getting up at about the same time each morning. Going to bed at different times each night and sleeping for different lengths of time at various times throughout the 24-hour day can increase your risk for developing one of these disorders.

The following sections look at these unusual conditions.

Dealing with an irregular sleep-wake pattern

Throughout this book, we emphasize the importance of maintaining a fairly regular sleeping and waking schedule to promote healthy sleep. When you don’t have a set time for going to bed and for waking up, you may develop a sleep disorder known as an irregular sleep-wake pattern, which can make falling asleep when you want and, worse yet, staying awake when you want very difficult.

People with irregular sleep-wake patterns have variable and disorganized periods of sleep and wakefulness. They usually fall asleep more than once a day, but at irregular intervals. They may awaken frequently during the night and take several daytime naps to compensate for their sleepiness.

Some people, like the shift workers and frequent flyers we discuss earlier in this chapter, may have significant difficulty maintaining regular bedtimes, but this is because of outside factors they can’t change. When outside factors cause irregular sleep-wake pattern, it’s called extrinsic irregular sleep-wake pattern. When internal factors, abnormal brain function, or a malfunctioning of the biological clock controlling the sleep-wake cycle cause the irregularity, it’s called intrinsic irregular sleep-wake pattern.

People who are bedridden and sleep on and off throughout the 24-hour day as well as retirees who don’t have a social or work routine can also end up confusing their nights and days.

How does an irregular sleep-wake pattern affect you?

People who have irregular sleep-wake pattern may drive their families nuts because their schedules are so unpredictable. Even they can’t tell when they’re going to feel alert or sleepy. Sleep just creeps up on them at odd times during the course of a 24-hour day. Even though they sleep just a few hours at a time, their total sleep time is normal, between seven and eight hours total for a 24-hour day.

Here are some symptoms to look for if you think you may have irregular sleep-wake pattern. People with irregular sleep-wake pattern

Have sleep cycles that are irregular and disorganized

May have as many as three distinct sleep-wake cycles in a 24-hour period

May also report episodes of insomnia, or extreme sleepiness

Treating an irregular sleep-wake pattern

Fortunately, this disorder is comparatively rare. Doctors treat it with bright-light therapy and by increasing outdoor activity and limiting daytime naps. Patients need to establish and maintain a regular schedule for going to sleep and waking up.

Handling advanced sleep-phase syndrome

Advanced sleep-phase syndrome (ASPS) is basically just the opposite of delayed sleep-phase syndrome. People with ASPS experience irresistible sleepiness early in the evening, as early as 6 to 8 p.m., and they simply must go to bed or they’ll fall over. Then, they pop up at 4 a.m., wide awake and raring to go. We may refer to people with ASPS as “larks” or “early birds,” but they don’t really get the worm, just a lot of grief from those around them about why they nod off so early in the evening.

Although people can develop ASPS at any age, it’s more common among older people.

As with DSPS, this out-of-sync sleep-wake pattern can make it difficult for the patient to maintain a normal lifestyle. It can also cause severe strain in family relationships. If mom and the kids want to go see a movie, but dad is keeled over in the recliner by 6:30 p.m., the sleeping can lead to conflict, especially if the awake spouse doesn’t understand that ASPS is an actual sleep disorder and her sleepy spouse doesn’t have any control over his sleep-wake pattern.

How does ASPS affect you?

In ASPS, the patient

Falls asleep before the desired time

Has a “normal” bedtime of 6 to 8 p.m.

Sleeps normally after asleep and has few or no awakenings

Wakes up long before the desired time, as early as 2 to 5 a.m., and can’t get back to sleep

May complain of excessive evening sleepiness or early morning–awakening insomnia (For more information about early morning awakening insomnia, see Chapter 4.)

May also complain of sleepiness interfering with family and social activities

May complain of sleep deprivation if job or social obligations force him or her to stay awake in the early evening hours

For a variety of reasons, the elderly have more difficulty sleeping than most people. If you have an elderly family member who goes to sleep and wakes up very early, have him or her checked for ASPS. Good treatments are available that can help adjust bedtimes to a more normal schedule.

Treating ASPS

The following therapies may help treat ASPS:

Bright-light therapy: Exposure to bright lights in the evening is very helpful in getting people with ASPS to adjust to a later bedtime.

Chronotherapy: Advancing the bedtime in daily increments until you achieve the desired bedtime.

Melatonin (or other chronobiotics): Patients take melatonin in the early morning (2 a.m. or so) when the awakening occurs.

Sedative hypnotics: Sleep medications known as sedative hypnotics can be very useful in helping people with ASPS when they wake up too early. For example, if you awaken at 1 a.m., you can take a prescription sleep medicine to help you get back to sleep for the rest of the night.

Looking at non-24-hour sleep-wake syndrome

Also known as hypernychthemeral syndrome, this rare disorder is characterized by disorganized and variable sleep patterns that deprive sleepers of the normal time cues that signal their bodies when it’s time to sleep. In fact, it’s most common among blind people who are unable to process light cues through their optic nerves.

Research has shown that people who suffer from this disorder have a biological clock that may cycle every 25 hours or longer, meaning they’re almost always out of sync with the natural rhythms of light and dark that humans use to reset their SCN each day.

How does non-24-hour sleep-wake syndrome affect you?

Each night, the patient goes to sleep one to two hours later than the night before, and wakes up one to two hours later each morning. His or her sleep cycles change continuously, cycling freely through the 24-hour day. Patients may have as many as three periods of sleep in one 24-hour period, but occasionally may be unaware, particularly if they’re blind, that anything is unusual about their sleep pattern.

Patients with non-24-hour sleep-wake syndrome seem to have a biological clock that’s out of sync with normal environmental cues such as light and dark.

They may also complain of the following:

Excessive sleepiness

Occasional insomnia

Inability to maintain a normal sleep-wake pattern

Treating non-24-hour sleep-wake syndrome

Treating blind patients for this condition is difficult because the normal treatment, bright-light therapy, is of little value to someone who can’t receive light signals through the optic nerve. But some evidence suggests that timed exposure to ultra bright lights may help some blind people. Most blind patients can benefit from the timed administration of melatonin supplements to reset their biological clocks.

For sighted people, the standard treatment is exposure to bright lights for two hours each morning, and avoidance of bright light for several hours before the desired bedtime. The light shifts the sleep-wake cycle and can help people with non-24-hour sleep-wake syndrome achieve a more normal bedtime and wake-up time. In addition, doctors instruct most patients to avoid napping.