Insomnia is a sleep disorder characterized by difficulties falling or staying asleep that affects a wide swath of the general population. A European study that surveyed 24,600 people from France, the United Kingdom, Germany, Italy, Portugal and Spain found that 27 percent of people reported difficulty falling asleep and 10 percent had trouble maintaining sleep at least three times per week.
However, using the standard, clinical definition of insomnia, it's much less common. When only those who experience sleeping difficulties for at least a month and don't have another disorder or work schedule that could account for the difficulties are included, the prevalence is estimated at about 6 percent of the population.
Compared to good sleepers, people with persistent sleep disturbances are more prone to traffic accidents, have higher rates of work absenteeism, diminished job satisfaction and are less able to handle minor irritations, according to a literature review conducted by the University of Rochester in February 2010.
Types and Causes
The International Classification of Sleep Disorders, second edition, categorizes several types of insomnia according to their frequency, duration and causes. Chronic insomnia means having symptoms at least three nights a week for more than a month. Acute insomnia lasts for a shorter time than that.
The most common type is “comorbid” insomnia. This type of insomnia is a symptom or side effect of other problems, such as psychiatric disorders, substance abuse, sleep apnea or restless leg syndrome.
Primary insomnia, where there isn't an identifiable co-existing disorder, is less common. A number of life changes can trigger primary insomnia, including long-lasting stress and emotional upset.
Diagnosis & Tests
There are several self-diagnosis tests available, with a daily sleep diary being the most useful one, according to the February 2010 review by the University of Rochester. Entries should include basic information such as what time you go to bed, how many minutes it takes to fall asleep, the number and duration of awakenings, total sleep time and what time you get out of bed. The diary should be kept over one to two weeks so that patterns, if there are any, can be determined.
A complete diagnosis by a physician would include thorough assessments of sleep, medical and psychiatric history stretching back to childhood and information from family members. To get a complete picture, it is also necessary to evaluate any current life stressors, work schedule patterns or specific events that precipitated the insomnia.
Some laboratory tests are available for investigating sleep disorders. However, according to conclusions from the National Institutes of Health, these methods are not entirely applicable for insomnia diagnosis. The actigraph, a wrist-worn device that registers nighttime movements that imply awakenings, is usually used for evaluating circadian rhythm disorders, and its use in insomnia is not yet fully validated.
Overnight polysomnographic recording, which measures various vital signs including brainwaves, heart rate, muscle movement and breathing rate, is the most sensitive tool for differentiating wakefulness and sleep. However, it is expensive and usually not necessary unless another sleep disorder, such as sleep apnea, is suspected.
Treatments & Medications
For the majority of people, acute insomnia usually resolves spontaneously. However, acute insomnia that lasts between two to four weeks can potentially develop into chronic insomnia, which does not typically resolve spontaneously.
Cognitive-behavioral therapies (CBTs) and prescription medication are effective tools towards managing chronic insomnia, according to the NIH. CBTs specifically target anxiety-producing beliefs, including anxieties over sleep and sleep loss.
Prescription hynoptics, such as flurazepam (known by its brand name, Dalmane) or zolpidem (Ambien) mimic the inhibitory actions of the neurotransmitter gamma-aminobutyric acid (GABA).
Antidepressants are also often prescribed as off-label remedies — in fact, the antidepressant trazodone (Desyrel) is a common treatment for insomnia according to the American Academy of Sleep Medicine. But the long-term effectiveness of antidepressants on chronic insomnia still needs conclusive data.
Over-the-counter remedies, such as antihistamines, are not recommended. There is no scientific evidence they are effective as a sleep-aid and there are significant concerns over adverse side effects, particularly in the elderly, according to the NIH.
The true effectiveness of natural remedies such as melatonin and valerian is also doubtful. Since these are not regulated by the FDA, it’s difficult to compare them to prescription medications. But according to the NIH, limited studies have shown no benefit compared to placebo.
Because insomnia commonly appears in the presence of other disorders, one should also consider treating and resolving any concurrent mental and physical health problems.
Regardless of the need for prescription medication or the severity of insomnia, a number of lifestyle changes can help improve the quality of sleep. For example, one should avoid spending more than 15 to 20 minutes awake in bed, retiring to bed early before feeling sleepy, using alcohol to induce sleep, napping or sleeping in. Habits such as cigarette smoking, alcohol and coffee consumption and certain prescription drugs can affect sleep quality and, it seems, altering these behaviors could help mitigate the frequency of insomnia. But evidence about whether these lifestyle changes can help resolve insomnia is still inconclusive.