Insomnia
Risk Factors, Diagnosis, & Treatment
IntroductionInsomnia is a common sleep disorder. It has both night time and daytime symptoms. Night time symptoms include persistent difficulties falling and / or staying asleep. Daytime symptoms include diminished sense of well being and compromised functioning due to fatigue. It is important to realize that not everyone who has problem sleeping has insomnia. The word persistent is emphasized because many people occasionally experience disturbed sleep at night but their problem is transient.
Insomnia is diagnosed when the problems persist for at least one month and chronic insomnia is diagnosed when the symptoms persist for at least 6 months. Chronic insomnia is present in approximately one in ten adults in the Unites States.
Insomnia involves difficulty sleeping despite being sleep deprived. Most people with insomnia are not able to catch up on lost sleep even if they try napping during the day [1]. A person with insomnia usually allocates enough time for sleep but is sleep deprived due to inability to obtain enough sleep. In contrast, when good sleepers are sleep deprived it is because they have not allocated enough time to sleep. They are usually able to make up some of the lost sleep by napping during the day. Interestingly, when people with insomnia are allowed to sleep only 80% of their average habitual sleep time, and therefore are even more sleep deprived than usual, they are better able to nap [2].
Some people naturally sleep 5 hours or less per night and report feeling alert and well throughout the day. These short sleepers do not have insomnia. They do not need more sleep. The ideal length of sleep is the amount of sleep that optimizes the sense of alertness and well being during the day. Different people need different amounts of sleep. The distribution of actual sleep time in adults is bell shaped. The 2002 Sleep in America Poll, conducted by the National Sleep Foundation, reports that American adults sleep an average of 6.9 hours per night on weekdays and 7.5 hours on the weekend.
The focus of this write up is on insomnia in adults. Many of the principles described below apply to children and adolescents as well, but there are some insomnia diagnoses specific to children that require treatments not covered in this article.
What promotes good sleep?To understand insomnia it is helpful to know what factors promote good sleep. The following three conditions need to co-exist for best sleep.
1) Attempt to sleep should be made only when feeling sleepy and calm. Feeling sleepy is a sign that the biological system that promotes wakefulness is operating at a low level. The biological systems that promote wakefulness and sleep are distinct. They do not constitute a single system with an on-off switch but the two systems interact. The wake promoting system can trump the sleep promoting system. This is adaptive. It allows us to adequately respond to dangerous threats that might emerge at night. Therefore, when we perceive threat in our environment, such as when we experience distress, it is difficult for us to sleep. On the other hand, when our stress level at bedtime is low we are likely to fall asleep easily. People differ in how they respond to stress.
Individuals with insomnia have abnormalities in the biological systems that are involved in reactions to stress. For example, compared with good sleepers, people with insomnia have higher metabolic levels and heart rates and higher levels of stress hormones [3][4]. The majority of people with insomnia report that they experience difficulty shutting their mind off at bed time, suggesting that their wake promoting system is operating at a high level when they try to sleep.
2) Bed time and rise time should be congruent with the biological clock that regulates sleep and wakefulness (also known as the circadian rhythm or the circadian clock). This clock operates by sending low and high alerting signals across the 24-hour day. The best time to go to bed is when the circadian clock sends weak alerting signals. The magnitude of this signal keeps going down during the night and then, approximately 2 hours before we naturally wake up, it starts going up.
Sometimes this biological clock is out of phase with society. People who describe themselves as “night owls” (approximately 10% of the adult population) often have a delayed circadian clock relative to most others. This means that the night owl’s alerting signal starts decreasing later than it does for most people. When night owls go to bed when most other people do, they are essentially trying to sleep when their alerting signal is still too high and therefore they have difficulty falling asleep. But if they wait and go to bed later they fall asleep much faster because their alerting signal is already decreasing. “Night owls” also have difficulty waking up in the morning. This happens because at the time they try to wake up their biological clocks are not yet generating strong alerting signals. There are also individuals who have clocks that run early. They typically describe themselves as “definitely a morning person”. It is possible to approximate people’s circadian clock with a questionnaire that determines to what extent one is a morning versus a night person. Examples of such questionnaires can be found here or here. (Laboratory procedures to actually asses the circadian clock are used in research but they are not practical outside research settings.)
3) Attempt to sleep should be made only after sufficient time has elapsed since the last sleep period. This is seldom an issue, except for people who sleep a lot during the day. As more time elapses after we wake up a sleep promoting brain chemical called adenosine accumulates. The best sleep occurs when the balance between sleep promoting and alerting or wake promoting signals is sufficiently tipped toward sleep promotion.
Types of insomnia
Insomnia is classified by duration:
* Transient Insomnia - Less than one month.
* Short-term Insomnia – Between 1 and 6 months
* Chronic Insomnia – More than 6 months
Insomnia is also classified by presumed cause:
* Primary insomnia – Insomnia that is present with no other co-existing disease. Most of the studies on treating insomnia have been done with people who have primary insomnia.
* Co-morbid insomnia– Insomnia that exists in the context of another medical or psychiatric condition. Co-morbid insomnia does not have to be caused by or change with the co-existing disorder. Most cases of insomnia belong to this category. Sometimes having insomnia can make the medical or psychiatric condition worse and hinder its treatment. For example, people with depression and insomnia do not respond as well to depression treatment as depressed people without insomnia [5].
How is insomnia diagnosed?The term insomnia is sometimes used colloquially in reference to disturbed sleep. An insomnia disorder is diagnosed when the disturbed sleep lasts more than a month and negatively impacts general well being, either because it is very distressing or because it leads to impairment in performance or mood. Sleep specialists can determine if the symptoms are not better explained by other disorders, including sleep, mental, or medical disorders.
There are several diagnostic systems for insomnia. Mental health providers, such as psychologists or psychiatrists, use the Diagnostic and Statistical Manual for Mental Disorders (DSM), which is published by the American Psychiatric Association. Sleep specialists use a different diagnostic system called the International Classification of Sleep Disorders (ICSD). The diagnostic categories in both systems are established by panels of experts who take into account available research and clinical experience. The current versions of both diagnostic systems include primary insomnia, insomnia related to another sleep disorder, insomnia related to another medical condition, insomnia related to another mental condition, and insomnia related to substance use. The current ICSD system also includes four subcategories of primary insomnia (psychophysiologic insomnia, paradoxical insomnia, idiopathic insomnia, & inadequate sleep hygiene).
When is an overnight sleep study needed?An over-night stay in the sleep laboratory is not necessary for a diagnosis of insomnia. However, sometimes a sleep study will be recommended. The most common reason for a referral to an over-night sleep study is a suspicion that another sleep disorder might be present (e.g., sleep apnea or periodic limb movements disorder). A sleep study is also recommended when sleep is not refreshing despite being of adequate length. Sleep specialists who oversee over-night sleep studies usually practice in a sleep center. Click here to find an AASM accredited sleep center near you.
Who is at risk for insomnia? o Individuals who have very irregular sleep wake schedules are at risk for developing insomnia because irregular sleep-wake schedules weaken the signals from the circadian clock regulating sleep and wakefulness. Those whose jobs involve frequent time zone changes or shift work are at particularly high risk.
o “Night owls” who do not have a regular wake time are at risk for insomnia.
o People with some medical or psychiatric conditions are at increased risk for insomnia. Depression and conditions that are associated with pain or physical discomfort are examples of such conditions.
o People who describe themselves as “worriers” are at risk for insomnia. Learning to set one’s worries aside can help reduce this risk.
o People who do not unwind from the day’s stresses are more likely to sleep poorly.
o People with other sleep disorders, such as restless legs syndrome and sleep apnea, are prone to insomnia
o People with genetic predisposition are also more likely to develop insomnia. There are no genetic tests that can identify those at risk for insomnia but twin studies show that genetics plays a role in insomnia [6].
o Women are twice as likely to experience insomnia as men.
o Older adults are more likely to experience insomnia.
How does insomnia start?Insomnia often develops during periods of distress. About 75% of people with insomnia can identify a trigger of their insomnia, most commonly health issues and stress related to family or work situations [7]. Poor sleep is a common reaction to stress but there are large individual differences in how people react to and cope with stress. These differences likely play a role in the development of insomnia.
Some health conditions can disrupt sleep. These include the following:
* Conditions that cause chronic pain, such as arthritis and headache disorder
* Conditions that are associated with difficulty breathing, such as asthma, congestive heart failure, chronic obstructive pulmonary diseases, and sleep apnea
* Depression, anxiety and other psychiatric disorders
* Abnormal thyroid function
* Acid reflux disorder
* Restless legs syndrome
* Conditions that increase urinary frequency, such as enlarged prostate
* Dementia
Certain medications and commonly used substances can disrupt sleep. These include the following:
* Caffeine, nicotine, and other stimulants
* Alcohol or other sedatives that wear off in the middle of the night
* Some asthma medications (e.g. theophylline)
* Some decongestants and allergy and cold medicines
* Some steroids, such as prednisone
* Beta blockers (medicines used to treat heart conditions)
Sleep disruptions that are caused by medical conditions, medications, and substances can resolve when the medical condition is treated. However, this is not always the case.
How does insomnia persist?Most of the time sleep normalizes after the stress that started it subsides or after the medical condition that caused it is treated. However, in some cases insomnia persists. This can happen in several ways.
1. The bed and the bedroom become linked with wakefulness, arousal, or negative emotions. This is known as conditioned arousal. The bed and the bedroom become unconscious cues for arousal rather than sleep. For example, many people with insomnia report that they dose off while watching TV or reading in the living room, only to become fully awake when they go to bed. For these people, past experience with tossing and turning while trying to sleep has made the the bed a cue for wakefulness rather than sleep. Conditioned arousal can develop even when the main problem is with staying asleep rather than initially falling asleep.
2. Some people react to poor sleep by trying harder. They extend the time they spend in bed, avoid evening activities that they used to enjoy, toss and turn in bed, and might even try a “night cap”. These strategies do not solve the problem. In fact, such strategies make it worse. Prolonged time in bed actually promotes wakefulness. The very act of "trying" produces frustration, increases arousal, and can become a hidden source of stress. This process is akin to a Chinese finger cuff. The harder you try to pull your fingers away, the more stuck they become. When you let go, you can ease your fingers out.
3. Worry about sleep is another common reaction to having sleep difficulty. After a period of not sleeping well, apprehension and concern that the coming night will be another struggle emerge. When unable to sleep, worries about the negative day time consequences of insufficient sleep develop. Such worries, though understandable, are activating and end up making sleep even more difficult.
Treating insomnia with medicationsThe Food and Drug Administration (FDA) has approved certain medications for the treatment of insomnia. These are called hypnotic medications or sleep medications. Below is a brief discussion of medications that are commonly used for sleep. The discussion is organized by classes of medication.
One class of sleep medication is called benzodiazepines. The following five medications, listed in alphabetical order, are approved by the FDA for the treatment of insomnia:
* Dalmane (flurazepam)
* Doral (quazepam)
* Halcion (triazolam)
* ProSom (estazolam)
* Restoril (temazepam)
Other benzodiazepine medications approved by the FDA for the treatment of anxiety, such as Ativan (lorazepam), Klonopin (clonazepam), and Xanax (alprazolam), are sometimes prescribed for insomnia as well. Benzodiazepines are generally recommended for short term use because tolerance and dependence can develop. In addition, some medications in this class can produce a “hangover” or grogginess on the following day.
For these reasons, newer sleep medications have been developed and approved by the FDA. Most of these newer medications work on the benzodiazepine receptors in the brain but do it more selectively than the medications in the benzodiazepine class. Therefore, these newer sleep medications are safer and have lower potential for dependence and fewer side effects. They are called “non-benzodiazepines”, a confusing name given that they still operate by acting on the benzodiazepine receptors. The “non-benzodiazepines” are:
* Ambien (zolpidem tartrate) & Ambien-CR (zolpidem tartrate extended release)
* Lunesta (eszopiclone)
* Sonata (zaleplon)
Some people experience grogginess in the morning even with sleep medications from this newer class. This happens because people differ in how they metabolize the medications. Grogginess in the morning occurs when a sleep medication is metabolized slowly and it is still active upon waking up in the morning. Because of their safety profile and their lower potential for dependence, some medications in this class are approved by the FDA for continuous long-term use.
Rozerum (ramelteon) is another new sleep medication. It has a very different mechanism of action. It affects the melatonin receptor in the brain.
Sometimes doctors prescribe a medication that is sedating even though it was not specifically developed to help with sleep. For example, a sedating antidepressant medication is often prescribed to help with insomnia. The most common antidepressants prescribed for sleep are Desyrel (trazodone), Sinequan (doxepine), and Amitriptyline (elavil). These medications are usually prescribed at doses that are lower than what is required for the treatment of depression and they do not lead to tolerance or drug dependence.
Some people use over-the-counter medications, which usually contain antihistamines, or natural remedies for insomnia. These remedies include herbs, such as valerian, and supplements, such as melatonin and L-tryptophan. The FDA does not regulate herbs and supplements. This means that their dose and purity are not monitored.
Discontinuing sleep medications: The best way to discontinue sleep medications that have been used for a long time is to do so gradually. Most of the newer sleep medications do not cause physical dependence but they can cause psychological dependence. An abrupt discontinuation of a sleep medication can cause a very fitful sleep on the first night or two after the discontinuation. The fitful night is often caused by the discontinuation itself and usually does not reflect the underlying insomnia. The bad nights caused by withdrawal lead many people to promptly resume the use of the sleep medications. The alternative is to slowly reduce the dose (e.g. 25% reduction per week). A small reduction in dose rarely produces noticeable difference in sleep quality. The small steps add up and before long, people can discontinue medications altogether [8].
Treating insomnia without medication Psychologists have developed and tested a specific therapy for insomnia called cognitive behavioral therapy for insomnia. Cognitive behavioral therapy is a specific psychotherapeutic approach with variants for treating different mental conditions, such as depression, anxiety, and eating disorders. In general, psychotherapies that are not insomnia focused are not very effective for treating chronic insomnia. When insomnia is experienced in the context of another disorder, such as depression, general psychotherapy might be effective in helping with depression but not be as helpful with the insomnia.
Cognitive behavioral therapy for insomnia Cognitive behavioral therapy guides patients through a series of changes in sleep-related behaviors. The focus is on addressing the three factors that contribute to the persistence of insomnia: 1) conditioned arousal, 2) identifying and eliminating habits that were developed in an effort to improve sleep but have become ineffective, and 3) reducing sleep-related worry and other sources of heightened arousal. The therapist identifies the most relevant targets for behavior changes and helps patients overcome obstacles to making the necessary and often difficult changes in sleep-related behaviors. This means that individual patients can concentrate their energy on changes that are most likely to produce improvements in their sleep. Sometimes the therapist helps patients re-evaluate beliefs about sleep that might be causing unnecessary anxiety.
The majority of patients respond to this treatment fairly quickly. Some experience significant changes after only two therapy sessions. Most improve after 4 to 6 sessions but some might need more sessions. Both group and individual treatments are effective.
Below is a list of some of the instructions and procedures used in this therapy:
o Stimulus control - This set of instructions addresses conditioned arousal. It was developed by Richard Bootzin. They are designed to strengthen the bed as a cue for sleep and weaken it as a cue for wakefulness. The key instructions are:
1. Establish a regular morning rise time. This will help strengthen the circadian clock regulating sleep and wakefulness. Ideally, bedtime should also be regular, but for people with insomnia it is impossible to actually fall asleep around the same time nightly. When insomnia resolves, regular bedtime can further strengthen the circadian rhythm.
2. Go to bed only when sleepy. This will increase the probability that you will fall asleep quickly. It is important to distinguish between fatigue and sleepiness. Fatigue is a state of low energy, physical or mental. Sleepiness is a state of having to struggle to stay awake. Dosing off while watching TV or as a passenger in a car involve sleepiness. People with insomnia often feel tired but “wired” (i.e. not sleepy) at bedtime.
3. If unable to fall asleep, either at the beginning or in the middle of the night, get out of bed and return to bed only when sleepy again.
4. Avoid excessive napping during the day. A brief nap (15 to 30 minutes), taken approximately 7 to 9 hours after rise time, can be refreshing and is not likely to disturb nocturnal sleep.
o Sleep Restriction - This procedure is designed to eliminate prolonged middle of the night awakenings 11. It was developed by Arthur Spielman. This procedure does not aim to restrict actual sleep time but rather to initially restrict the time spent in bed. Subsequent steps consist of gradually increasing the time spent in bed. The initial time in bed is usually the average nightly total sleep time over the last week. However, the time allowed in bed should not be less than 5.5 hours, even for people who sleep less than 5.5 hours per night.
For example, consider a person who goes to bed at 11:00 p.m. and gets out of bed at 8:00 a.m. but sleeps on average only 6 hours per night. During the first step of this procedure this person will be in bed only 6 hours (e.g., 12:00 am to 6:00 am). This sounds harsh but after a week or so there will be a marked decrease in time spent awake in the middle of the night.
Usually people experience marked improvement in the quality of sleep after a week of restricted time in bed but they also realize that that they are not getting enough sleep. In this case, the next step is to gradually extend the time spent in bed by 15 to 30 minutes, as long as wakefulness in the middle of the night remains minimal.
Each new extension of the time in bed is followed for at least a week before progressing to the next extension. The decision as to when to extend the time in bed is based on the percent of the time slept relative to the time spent in bed. This is called sleep efficiency. If the average sleep efficiency is 85% or more, then the time in bed is extended. If it is below 80% then the time is bed is further restricted. Otherwise the time in bed remains unchanged. There are several variants of this procedure from which the therapist chooses the one that best fits individual patients. In all variants, the procedure continues until one reaches a point after which no further extension is necessary because the amount of sleep obtained is sufficient for optimal daytime function.
o Reducing sleep interfering arousal /activation - These include a variety of relaxation techniques, stress management skills, and reducing sleep-related worries. The behavioral sleep medicine specialist uses cognitive therapy to reduce arousal by helping patients shift from “trying hard to sleep” to “allowing sleep to happen”. In addition, the following can also facilitate sleep:
+ Use the hour before bedtime to unwind from the day’s stresses. This down time will allow sleepiness to come to the surface and will therefore facilitate sleep onset. This is a time to engage in activities that are enjoyable yet calming.
+ Avoid clock watching. Turn the clock around so you cannot see the time yet you can still use it as an alarm. A recent study showed that volunteers who were asked to monitor a digital clock at bedtime took longer to fall asleep than those monitoring a similarly looking device that displayed random digits 12.
+ Avoid exercise 4 hours before bedtime.
+ Make sure that the sleep environment is safe, quiet, and pleasant.
o About foods and substances + Alcohol: Alcohol speeds sleep onset but this positive effect is counteracted by increased wakefulness in the second half of the night.
+ Stimulants: Caffeine has a rather long half-life (about 6 to 8 hours). People’s sensitivity to the effects of caffeine is variable. Those with caffeine sensitivity should be particularly careful to avoid caffeine after lunch. (The amount of caffeine in different drinks and recommendations regarding caffeine consumption can be found on the the National Sleep Foundation website.) Certain prescription and non-prescription drugs contain caffeine and when feasible should be avoided close to bedtime. Nicotine and nicotine withdrawal can also interfere with sleep.
+ Eating at night: Digestion slows down during sleep and indigestion, caused by undigested food, can disrupt sleep. Eating in the middle of the night sends the body an alerting signal.
o Taking the biological clock into account - Bed time and rise time should be congruent with one’s circadian clock. When the desired bed time and rise time are not aligned with the circadian clock the therapist can use procedures to shift the circadian clock, such as properly timed exposure to bright light.
Professional help should be sought by people who find it impossible to follow the above recommendations consistently. For example, some people say they never get sleepy. Others find it too hard to get out of bed at the same time every day.
Therapists with special training in sleep disorders and behavioral sleep medicine are best situated to help people with insomnia because they possess knowledge in the science of sleep and the science of behavior change. The American Academy of Sleep Medicine has established a certification in Behavioral Sleep Medicine and maintains a list of certified specialists and their geographic location on its web site. To find an insomnia therapist near you click here.
Comparing sleep medication with non-medication treatment of insomnia
Both sleep medications and cognitive behavioral therapy for insomnia (CBT-I) are effective. The two have produced similar levels of improvement for primary insomnia after 6 to 8 weeks of treatment [9][10]. Sleep medications start working right away, whereas the benefits of CBT-I are slower to emerge. On the other hand, the effects of CBT-I are longer lasting after treatment is discontinued. Six to 24 months after the end of treatment people originally treated with CBT-I sleep better than those originally treated with medication [9][10].
Resources
The following are select books and informative web sites about insomnia and sleep.
Self help books for insomnia:
1. Colleen Carney & Rachel Manber: Quiet Your Mind and Get to Sleep: Solutions to Insomnia for Those with Depression, Anxiety, or Chronic Pain
2. Paul Glovinsky & Art Spielman: The Insomnia Answer: A Personalized Program for Identifying and Overcoming the Three Types of Insomnia
3. Charles Morin: Relief from insomnia
4. Peter Hauri & Shirley Linde: No More Sleepless Nights
5. Gregg D. Jacobs and Herbert Benson: Say Good Night to Insomnia: The Six-Week, Drug-Free Program Developed At Harvard Medical School
Books about sleep:
1. William Dement, The Promise of Sleep
2. Peretz Lavie, The Enchanted World of Sleep
Web Resources:
* National Institutes of Health: NIH State-of-the-Science Conference Statement on Manifestations and Management of Chronic Insomnia in Adults, June 13–15, 2005:
* National Heart, Lung, and Blood Institute: Disease and conditions Index, Insomnia
* National Heart, Lung, & Blood Institute: Your Guide to healthy Sleep
* National Sleep Foundation: ABCs of ZZZZs -- When you Can't Sleep
* The Journal of the American Medical Association (JAMA): Insomnia
* The American Academy of Sleep Medicine: Sleep education
* National Sleep Foundation: Sleep-Wake Cycle: Its Physiology and Impact on Health
References
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2. Bonnet MH, Arand DL. The consequences of a week of insomnia. II: Patients with insomnia. Sleep. Jun 15 1998;21(4):359-368.
3. Bonnet MH, Arand DL. 24-hour metabolic rate in insomniacs and matched normal sleepers. Sleep. 1995;18:581-588.
4. Vgontzas AN, Chrousos GP. Sleep, the hypothalamic-pituitary-adrenal axis, and cytokines: multiple interactions and disturbances in sleep disorders. Endocrinol Metab Clin North Am. 2002;31:15-36.
5. Dew MA, Reynolds CF, Houck PR, et al. Temporal profiles of the course of depression during treatment. Predictors of pathways toward recovery in the elderly. Arch Gen Psychiatry. 1997;54(11):1016-1024.
6. Watson NF, Goldberg J, Arguelles L, Buchwald D. Genetic and environmental influences on insomnia, daytime sleepiness, and obesity in twins. Sleep. May 1 2006;29(5):645-649.
7. Bastien CH, Vallieres A, Morin CM. Precipitating factors of insomnia. Behav Sleep Med. 2004;2(1):50-62.
8. Morin CM, Bastien C, Guay B, et al. Randomized clinical trial of supervised tapering and cognitive behavior therapy to facilitate benzodiazepine discontinuation in older adults with chronic insomnia. Am J Psychiatry. Feb 2004;161(2):332-342.
9. Morin C, Colecchi C, Stone J, Sood R. Behavioral and Pharmacological Therapies for Late-Life Insomnia: A Randomized Controlled Trial. JAMA. 1999;281:991-999.
10. Sivertsen B, Omvik S, Pallesen S, et al. Cognitive behavioral therapy vs zopiclone for treatment of chronic primary insomnia in older adults: a randomized controlled trial. JAMA. Jun 28 2006;295(24):2851-2858.
