Insomnia, additionally known as sleeplessness, is a sleep disorder where people have trouble sleeping. They might have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, irritability, and a depressed mood. It might result in an increased risk of motor vehicle collisions, as well as problems focusing and learning. Insomnia can be short term, lasting for days or weeks, or long term, lasting more than a month.

Insomnia can occur independently or as a result of another problem. Conditions that can result in insomnia include psychological stress, chronic pain, heart failure, hyperthyroidism, heartburn, restless leg syndrome, menopause, certain medications, and drugs such as caffeine, nicotine, and alcohol. Other risk factors include working night shifts and sleep apnea. Diagnosis is based on sleep habits and an examination to look for underlying causes. A sleep study might be done to look for underlying sleep disorders. Screening might be done with two questions: "do you experience difficulty sleeping?" and "do you have difficulty falling or staying asleep?"

Sleep hygiene and lifestyle changes are typically the first treatment for insomnia. Sleep hygiene includes a consistent bedtime, exposure to sunlight, a quiet and dark room, and regular exercise. Cognitive behavioural therapy might be added to this. While sleeping pills might help, they're associated with injuries, dementia, and addiction. Medications aren't recommended for more than four or five weeks. The effectiveness and safety of alternative medicine is unclear.

Between ten percent and thirty percent of adults have insomnia at any given point in time and up to half of people have insomnia in a given year. About six percent of people have insomnia that isn't due to another problem and lasts for more than a month. People over the age of 65 are affected more often than younger people. Females are more often affected than males. Descriptions of insomnia occur at least as far back as ancient Greece.

Classification

DSM-5 criteria

The DSM-5 criteria for insomnia include the following:

Predominant complaint of dissatisfaction with sleep quantity or quality, associated with one (or more) of the following symptoms:

  • Difficulty initiating sleep. (In children, this might manifest as difficulty initiating sleep without caregiver intervention.)
  • Difficulty maintaining sleep, characterised by frequent awakenings or problems returning to sleep after awakenings. (In children, this might manifest as difficulty returning to sleep without caregiver intervention.)
  • Early-morning awakening with inability to return to sleep.

In addition,

  • The sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, behavioral, or additional important areas of functioning.
  • The sleep difficulty occurs at least 3 nights per week.
  • The sleep difficulty is present for at least 3 months.
  • The sleep difficulty occurs notwithstanding adequate opportunity for sleep.
  • The insomnia isn't better explained by and doesn't occur exclusively throughout the course of another sleep-wake disorder (e.g., narcolepsy, a breathing-related sleep disorder, a circadian rhythm sleep-wake disorder, a parasomnia).
  • The insomnia isn't attributable to the physiological effects of a substance (e.g., a drug of abuse, a medication).
  • Coexisting mental disorders and medical conditions don't adequately explain the predominant complaint of insomnia.

Types

Insomnia can be classified as transient, acute, or chronic.

  1. Transient insomnia lasts for less than a week. It can be caused by another disorder, by changes in the sleep environment, by the timing of sleep, severe depression, or by stress. Its consequences – sleepiness and impaired psychomotor performance – are similar to those of sleep deprivation.
  2. Acute insomnia is the inability to consistently sleep well for a period of less than a month. Insomnia is present when there's difficulty initiating or maintaining sleep or when the sleep that's obtained is non-refreshing or of poor quality. These problems occur notwithstanding adequate opportunity and circumstances for sleep and they must result in problems with daytime function. Acute insomnia is additionally known as short term insomnia or stress related insomnia.
  3. Chronic insomnia lasts for longer than a month. It can be caused by another disorder, or it can be a primary disorder. People with high levels of stress hormones or shifts in the levels of cytokines are more likely than others to have chronic insomnia. Its effects can vary according to its causes. They might include muscular weariness, hallucinations, and/or mental fatigue. Chronic insomnia can cause double vision.

Patterns

Symptoms of insomnia:

  • difficulty falling asleep, including difficulty finding a comfortable sleeping position
  • waking throughout the night and being unable to return to sleep
  • feeling unrefreshed upon waking
  • daytime sleepiness, irritability or anxiety

Sleep-onset insomnia is difficulty falling asleep at the beginning of the night, often a symptom of anxiety disorders. Delayed sleep phase disorder can be misdiagnosed as insomnia, as sleep onset is delayed to much later than normal while awakening spills over into daylight hours.

It is common for patients who have difficulty falling asleep to additionally have nocturnal awakenings with difficulty returning to sleep. Two thirds of these patients wake up in the middle of the night, with more than half having trouble falling back to sleep after a middle-of-the-night awakening.

Early morning awakening is an awakening occurring earlier (more than 30 minutes) than desired with an inability to go back to sleep, and before total sleep time reaches 6.5 hours. Early morning awakening is often a characteristic of depression.

Poor sleep quality

Poor sleep quality can occur as a result of, for example, restless legs, sleep apnea or major depression. Poor sleep quality is caused by the individual not reaching stage 3 or delta sleep which has restorative properties.

Major depression leads to alterations in the function of the hypothalamic-pituitary-adrenal axis, causing excessive release of cortisol which can lead to poor sleep quality.

Nocturnal polyuria, excessive nighttime urination, can be quite disturbing to sleep.

Subjectivity

Some cases of insomnia aren't really insomnia in the traditional sense. People experiencing sleep state misperception often sleep for normal durations, yet overestimate the time taken to fall and remain asleep.

Causes

Symptoms of insomnia can be caused by or be associated with:

Sleep studies using polysomnography have suggested that people who have sleep disruption have elevated nighttime levels of circulating cortisol and adrenocorticotropic hormone. They additionally have an elevated metabolic rate, which doesn't occur in people who don't have insomnia but whose sleep is intentionally disrupted throughout a sleep study. Studies of brain metabolism using positron emission tomography (PET) scans indicate that people with insomnia have higher metabolic rates by night and by day. The question remains whether these changes are the causes or consequences of long-term insomnia.

Substance-induced

Alcohol-induced

Alcohol is often used as a form of self-treatment of insomnia to induce sleep. Notwithstanding alcohol use to induce sleep can be a cause of insomnia. Long-term use of alcohol is associated with a decrease in NREM stage 3 and 4 sleep as well as suppression of REM sleep and REM sleep fragmentation. Frequent moving between sleep stages occurs, with awakenings due to headaches, the need to urinate, dehydration, and excessive sweating. Glutamine rebound additionally plays a role as when someone is drinking; alcohol inhibits glutamine, one of the body's natural stimulants. When the person stops drinking, the body tries to make up for lost time by producing more glutamine than it needs. The increase in glutamine levels stimulates the brain while the drinker is trying to sleep, keeping him/her from reaching the deepest levels of sleep. Stopping chronic alcohol use can additionally lead to severe insomnia with vivid dreams. During withdrawal REM sleep is typically exaggerated as part of a rebound effect.

Benzodiazepine-induced

Like alcohol, benzodiazepines, such as alprazolam, clonazepam, lorazepam and diazepam, are commonly used to treat insomnia in the short-term (both prescribed and self-medicated), but worsen sleep in the long-term. While benzodiazepines can put people to sleep (i.e., inhibit NREM stage 1 and 2 sleep), while asleep, the drugs disrupt sleep architecture: decreasing sleep time, delaying time to REM sleep, and decreasing deep slow-wave sleep (the most restorative part of sleep for both energy and mood).

Opioid-induced

Opioid medications such as hydrocodone, oxycodone, and morphine are used for insomnia that's associated with pain due to their analgesic properties and hypnotic effects. Opioids can fragment sleep and decrease REM and stage 2 sleep. By producing analgesia and sedation, opioids might be appropriate in carefully selected patients with pain-associated insomnia. Notwithstanding dependence on opioids can lead to long-term sleep disturbances.

Risk factors

Insomnia affects people of all age groups but people in the following groups have a higher chance of acquiring insomnia.

  • Individuals older than 60
  • History of mental health disorder including depression, etc.
  • Emotional stress
  • Working late night shifts
  • Travelling through different time zones

Mechanism

Cortisol

Cortisol is typically thought of as the stress hormone in humans, but it is additionally the awakening hormone. Analyzing saliva samples taken in the morning has shown that patients with insomnia wake up with significantly lower cortisol levels when compared to a control group with regular sleeping patterns. Further studies have revealed that those with lower levels of cortisol upon awakening additionally have poorer memory consolidation in comparison to those with normal levels of cortisol. Studies support that larger amounts of cortisol released in the evening occurs in primary insomnia. In this case, drugs related to calming mood disorders or anxiety, such as antidepressants, would regulate the cortisol levels and help prevent insomnia.

Estrogen

Many postmenopausal women have reported changes in sleep patterns after entering menopause that reflect symptoms of insomnia. This could occur because of the lower levels of estrogen. Lower oestrogen levels can cause hot flashes, change in stress reactions, or overall change in the sleep cycle, which all could contribute to insomnia. Estrogen treatment as well as estrogen-progesterone combination supplements as a hormone replacement therapy can help regulate menopausal women’s sleep cycle again.

Progesterone

Low levels of progesterone throughout the female menstruation cycle, but primarily near the end of the luteal phase, have additionally been known to correlate with insomnia as well as aggressive behavior, irritability, and depressed mood in women. Around 67 percent of women have problems with insomnia right before or throughout their menstrual cycle. Lower levels of progesterone can, like estrogen, correlate with insomnia in menopausal women.

A common misperception is that the amount of sleep required decreases as a person ages. The ability to sleep for long periods, rather than the need for sleep, appears to be lost as people get older. Some elderly insomniacs toss and turn in bed and occasionally fall off the bed at night, diminishing the amount of sleep they receive.

Diagnosis

In medicine, insomnia is widely measured using the Athens insomnia scale. It is measured using eight different parameters related to sleep, finally it is represented as an overall scale which assess an individual's sleep pattern.

A qualified sleep specialist should be consulted in the diagnosis of any sleep disorder so the appropriate measures can be taken. Past medical history and a physical examination need to be done to eliminate additional conditions that can be the cause of the insomnia. After all additional conditions are ruled out a comprehensive sleep history should be taken. The sleep history should include sleep habits, medications (prescription and non-prescription), alcohol consumption, nicotine and caffeine intake, co-morbid illnesses, and sleep environment. A sleep diary can be used to keep track of the individual's sleep patterns. The diary should include time to bed, total sleep time, time to sleep onset, number of awakenings, use of medications, time of awakening and subjective feelings in the morning. The sleep diary can be replaced or validated by the use of out-patient actigraphy for a week or more, using a non-invasive device that measures movement.

Workers who complain of insomnia shouldn't routinely have polysomnography to screen for sleep disorders. This test might be indicated for patients with symptoms in addition to insomnia, including sleep apnea, obesity, a risky neck diameter, or risky fullness of the flesh in the oropharynx. Usually, the test isn't needed to make a diagnosis, and insomnia especially for working people can often be treated by changing a job schedule to make time for sufficient sleep and by improving sleep hygiene.

Some patients might need to do a sleep study to determine if insomnia is present. The sleep study will involve the assessment tools of a polysomnogram and the multiple sleep latency test and will be conducted in a sleep centre or a designated hotel. Specialists in sleep medicine are qualified to diagnose the a large number of different sleep disorders. Patients with various disorders, including delayed sleep phase syndrome, are often mis-diagnosed with primary insomnia. When a person has trouble getting to sleep and awakening early, but has a normal sleep pattern once asleep, a delayed circadian rhythm is the likely cause.

In a large number of cases, insomnia is co-morbid with another disease, side-effects from medications, or a psychological problem. Approximately half of all diagnosed insomnia is related to psychiatric disorders. In depression in a large number of cases "insomnia should be regarded as a co-morbid condition, rather than as a secondary one;" insomnia typically predates psychiatric symptoms. "In fact, it is possible that insomnia represents a significant risk for the development of a subsequent psychiatric disorder." Insomnia occur in between sixty percent and eighty percent of people with depression. This might partly be due to treatment used for depression.

Knowledge of causation isn't necessary for a diagnosis.

Prevention

Going to sleep and waking up at the same time every day can create a steady pattern which might help to prevent or treat insomnia. Avoidance of vigorous exercise and any caffeinated drinks a few hours before going to sleep is recommended, while exercise earlier in the day is beneficial. The bedroom should be cool and dark, and the bed should only be used for sleep and sex. These are a few of the points included in what doctors call "sleep hygiene".

Treatment

It is important to identify or rule out medical and psychological causes before deciding on the treatment for insomnia. Cognitive behavioural therapy (CBT) has been found to be as effective as medications for the short-term treatment of chronic insomnia. The beneficial effects, in contrast to those produced by medications, might last well beyond the stopping of therapy. Medications have been used mainly to reduce symptoms in insomnia of short duration; their role in the management of chronic insomnia remains unclear. Several different types of medications are additionally effective for treating insomnia. Notwithstanding a large number of doctors don't recommend relying on prescription sleeping pills for long-term use. It is additionally important to identify and treat additional medical conditions that might be contributing to insomnia, such as depression, breathing problems, and chronic pain.

Non-pharmacological

Non-pharmacological strategies have comparable efficacy to hypnotic medication for insomnia and they might have longer lasting effects. Hypnotic medication is only recommended for short-term use because dependence with rebound withdrawal effects upon discontinuation or tolerance can develop.

Non pharmacological strategies provide long lasting improvements to insomnia and are recommended as a first line and long term strategy of management. The strategies include attention to sleep hygiene, stimulus control, behavioural interventions, sleep-restriction therapy, paradoxical intention, patient education and relaxation therapy. Some examples are keeping a journal, restricting the time spent awake in bed, practising relaxation techniques, and maintaining a regular sleep schedule and a wake-up time. Behavioral therapy can assist a patient in developing new sleep behaviours to improve sleep quality and consolidation. Behavioral therapy might include, learning healthy sleep habits to promote sleep relaxation, undergoing light therapy to help with worry-reduction strategies and regulating the circadian clock.

Music might improve insomnia in adults. EEG biofeedback has demonstrated effectiveness in the treatment of insomnia with improvements in duration as well as quality of sleep. Self-help therapy (defined as a psychological therapy that can be worked through on one's own) might improve sleep quality for adults with insomnia to a small or moderate degree.

Stimulus control therapy is a treatment for patients who have conditioned themselves to associate the bed, or sleep in general, with a negative response. As stimulus control therapy involves taking steps to control the sleep environment, it is at times referred interchangeably with the concept of sleep hygiene. Examples of such environmental modifications include using the bed for sleep or sex only, not for activities such as reading or watching television; waking up at the same time every morning, including on weekends; going to bed only when sleepy and when there's a high likelihood that sleep will occur; leaving the bed and beginning an activity in another location if sleep doesn't result in a reasonably brief period of time after getting into bed (commonly ~20 min); reducing the subjective effort and energy expended trying to fall asleep; avoiding exposure to bright light throughout nighttime hours, and eliminating daytime naps.

A component of stimulus control therapy is sleep restriction, a technique that aims to match the time spent in bed with actual time spent asleep. This technique involves maintaining a strict sleep-wake schedule, sleeping only at certain times of the day and for specific amounts of time to induce mild sleep deprivation. Complete treatment usually lasts up to 3 weeks and involves making oneself sleep for only a minimum amount of time that they're actually capable of on average, and then, if capable (i.e. when sleep efficiency improves), slowly increasing this amount (~15 min) by going to bed earlier as the body attempts to reset its internal sleep clock. Bright light therapy, which is often used to help early morning wakers reset their natural sleep cycle, can additionally be used with sleep restriction therapy to reinforce a new wake schedule. Although applying this technique with consistency is difficult, it can have a positive effect on insomnia in motivated patients.

Paradoxical intention is a cognitive reframing technique where the insomniac, instead of attempting to fall asleep at night, makes every effort to stay awake (i.e. essentially stops trying to fall asleep). One theory that might explain the effectiveness of this method is that by not voluntarily making oneself go to sleep, it relieves the performance anxiety that arises from the need or requirement to fall asleep, which is meant to be a passive act. This technique has been shown to reduce sleep effort and performance anxiety and additionally lower subjective assessment of sleep-onset latency and overestimation of the sleep deficit (a quality found in a large number of insomniacs).

Sleep hygiene

Sleep hygiene is a common term for all of the behaviours which relate to the promotion of good sleep. These behaviours are used as the basis of sleep interventions and are the primary focus of sleep education programs. Behaviors include the use of caffeine, nicotine and alcohol consumption, maximising the regularity and efficiency of sleep episodes, minimising medication usage and daytime napping, the promotion of regular exercise, and the facilitation of a positive sleep environment. Exercise can be helpful when establishing a routine for sleep but shouldn't be done close to the time that you're planning on going to sleep. The creation of a positive sleep environment might additionally be helpful in reducing the symptoms of insomnia. In order to create a positive sleep environment one should remove objects that can cause worry or distressful thoughts from view.

Cognitive behavioural therapy

There is a few evidence that cognitive behavioural therapy for insomnia is superior in the long-term to benzodiazepines and the nonbenzodiazepines in the treatment and management of insomnia. In this therapy, patients are taught improved sleep habits and relieved of counter-productive assumptions about sleep. Common misconceptions and expectations that can be modified include: (1) unrealistic sleep expectations (e.g., I need to have 8 hours of sleep each night), (2) misconceptions about insomnia causes (e.g., I have a chemical imbalance causing my insomnia), (3) amplifying the consequences of insomnia (e.g., I can't do anything after a bad night's sleep), and (4) performance anxiety after trying for so long to have a good night's sleep by controlling the sleep process. Numerous studies have reported positive outcomes of combining cognitive behavioural therapy for insomnia treatment with treatments such as stimulus control and the relaxation therapies. Hypnotic medications are equally effective in the short-term treatment of insomnia but their effects wear off over time due to tolerance. The effects of CBT-I have sustained and lasting effects on treating insomnia long after therapy has been discontinued. The addition of hypnotic medications with CBT-I adds no benefit in insomnia. The long lasting benefits of a course of CBT-I shows superiority over pharmacological hypnotic drugs. Even in the short term when compared to short-term hypnotic medication such as zolpidem (Ambien), CBT-I still shows significant superiority. Thus CBT-I is recommended as a first line treatment for insomnia. Metacognition is additionally a recent trend in approach to behaviour therapy of insomnia.

Internet interventions

Despite the therapeutic effectiveness and proven success of CBT, treatment availability is significantly limited by a lack of trained clinicians, poor geographical distribution of knowledgeable professionals, and expense. One way to potentially overcome these barriers is to use the Internet to deliver treatment, making this effective intervention more accessible and less costly. The Internet has already become a critical source of health-care and medical information. Although the vast majority of health websites provide general information, there's growing research literature on the development and evaluation of Internet interventions.

These online programmes are typically behaviorally-based treatments that have been operationalized and transformed for delivery via the Internet. They are usually highly structured; automated or human supported; based on effective face-to-face treatment; personalised to the user; interactive; enhanced by graphics, animations, audio, and possibly video; and tailored to provide follow-up and feedback.

There is good evidence for the use computer based CBT for insomnia.

Medications

Many people with insomnia use sleeping tablets and additional sedatives. In a few places medications are prescribed in over 95 percent of cases. They; however, are a second line treatment.

The percentage of adults using a prescription sleep aid increases with age. During 2005–2010, about four percent of U.S. adults aged 20 and over reported that they took prescription sleep aids in the past 30 days. Rates of use were lowest among the youngest age group (those aged 20–39) at about 2%, increased to six percent among those aged 50–59, and reached seven percent among those aged 80 and over. More adult women (5.0%) reported using prescription sleep aids than adult men (3.1%). Non-Hispanic white adults reported higher use of sleep aids (4.7%) than non-Hispanic black (2.5%) and Mexican-American (2.0%) adults. No difference was shown between non-Hispanic black adults and Mexican-American adults in use of prescription sleep aids.

Antihistamines

As an alternative to taking prescription drugs, a few evidence shows that an average person seeking short-term help might find relief by taking over-the-counterantihistamines such as diphenhydramine or doxylamine. Diphenhydramine and doxylamine are widely used in nonprescription sleep aids. They are the most effective over-the-counter sedatives currently available, at least in the United States, and are more sedating than a few prescription hypnotics. Antihistamine effectiveness for sleep might decrease over time, and anticholinergic side-effects (such as dry mouth) might additionally be a drawback with these particular drugs. While addiction doesn't seem to be an issue with this class of drugs, they can induce dependence and rebound effects upon abrupt cessation of use.

Melatonin

The evidence for melatonin in treating insomnia is generally poor. There is low quality evidence that it might speed the onset of sleep by 6 minutes. Ramelteon, a melatonin receptor agonist, doesn't appear to speed the onset of sleep or the amount of sleep a person gets.

Most melatonin drugs haven't been tested for longitudinal side effects. Prolonged-release melatonin might improve quality of sleep in older people with minimal side effects.

Studies have additionally shown that children who're on the Autism spectrum or have learning disabilities, Attention-Deficit Hyperactivity Disorder (ADHD) or related neurological diseases can benefit from the use of melatonin. This is because they often have trouble sleeping due to their disorders. For example, children with ADHD tend to have trouble falling asleep because of their hyperactivity and, as a result, tend to be tired throughout most of the day. An Additional cause of insomnia in children with ADHD is the use of stimulants used to treat their disorder. Children who have ADHD then, as well as the additional disorders mentioned, might be given melatonin before bedtime in order to help them sleep.

Antidepressants

Because insomnia is a common symptom of depression, antidepressants are effective for treating sleep problems whether or not they're associated with depression. While all antidepressants help regulate sleep, a few antidepressants such as amitriptyline, doxepin, mirtazapine, and trazodone can have an immediate sedative effect, and are prescribed to treat insomnia. Amitriptyline and doxepin both have antihistaminergic, anticholinergic, and antiadrenergic properties, which contribute to both their therapetuic effects and side effect profiles, while mirtazapine's side effects are primarily antihistaminergic, and trazodone's side-effects are primarily antiadrenergic. Mirtazapine is known to decrease sleep latency (i.e., the time it takes to fall asleep), promoting sleep efficiency and increasing the total amount of sleeping time in people with both depression and insomnia.

Agomelatine, a melatonergic antidepressant with sleep-improving qualities that doesn't cause daytime drowsiness, is licenced for marketing in the European Union and TGAAustralia. After trials in the United States its development for use there was discontinued in October 2011 by Novartis, who had bought the rights to market it there from the European pharmaceutical company Servier.

Benzodiazepines

Normison (temazepam) is a benzodiazepine commonly prescribed for insomnia and additional sleep disorders.

The most commonly used class of hypnotics for insomnia are the benzodiazepines. Benzodiazepines are not significantly better for insomnia than antidepressants. Chronic users of hypnotic medications for insomnia don't have better sleep than chronic insomniacs not taking medications. In fact, chronic users of hypnotic medications have more regular nighttime awakenings than insomniacs not taking hypnotic medications. Many have concluded that these drugs cause an unjustifiable risk to the individual and to public health and lack evidence of long-term effectiveness. It is preferred that hypnotics be prescribed for only a few days at the lowest effective dose and avoided altogether wherever possible, especially in the elderly. Between 1993 and 2010, the prescribing of benzodiazepines to individuals with sleep disorders has decreased from twenty-four percent to eleven percent in the US, coinciding with the first release of nonbenzodiazepines.

The benzodiazepine and nonbenzodiazepinehypnotic medications additionally have a number of side-effects such as day time fatigue, motor vehicle crashes and additional accidents, cognitive impairments and falls and fractures. Elderly people are more sensitive to these side-effects. Some benzodiazepines have demonstrated effectiveness in sleep maintenance in the short term but in the longer term benzodiazepines can lead to tolerance, physical dependence, benzodiazepine withdrawal syndrome upon discontinuation, and long-term worsening of sleep, especially after consistent usage over long periods of time. Benzodiazepines, while inducing unconsciousness, actually worsen sleep as—like alcohol—they promote light sleep while decreasing time spent in deep sleep. A further problem is, with regular use of short-acting sleep aids for insomnia, daytime rebound anxiety can emerge. Although there's little evidence for benefit of benzodiazepines in insomnia compared to additional treatments and evidence of major harm, prescriptions have continued to increase. This is likely due to their addictive nature, both due to misuse and because—through their rapid action, tolerance and withdrawal—they can "trick" insomniacs into thinking they're helping with sleep. There is a general awareness that long-term use of benzodiazepines for insomnia in most people is inappropriate and that a gradual withdrawal is usually beneficial due to the adverse effects associated with the long-term use of benzodiazepines and is recommended whenever possible.

Benzodiazepines all bind unselectively to the GABAA receptor. Some theorise that certain benzodiazepines (hypnotic benzodiazepines) have significantly higher activity at the α1 subunit of the GABAA receptor compared to additional benzodiazepines (for example, triazolam and temazepam have significantly higher activity at the α1 subunit compared to alprazolam and diazepam, making them superior sedative-hypnotics – alprazolam and diazepam in turn have higher activity at the α2 subunit compared to triazolam and temazepam, making them superior anxiolytic agents). Modulation of the α1 subunit is associated with sedation, motor-impairment, respiratory depression, amnesia, ataxia, and reinforcing behaviour (drug-seeking behavior). Modulation of the α2 subunit is associated with anxiolytic activity and disinhibition. For this reason, certain benzodiazepines might be better suited to treat insomnia than others.

Benzodiazepine-like medications

Drugs that might prove more effective and safer than benzodiazepines for insomnia is an area of active research. Nonbenzodiazepine sedative-hypnotic drugs, such as zolpidem (Ambien), zaleplon, zopiclone (Imovane), and eszopiclone (Lunesta), are a class hypnotic medications that are similar to benzodiazepines in their mechanism of action, and indicated for mild to moderate insomnia. Their effectiveness at improving time to sleeping is slight, and they have similar—though potentially less severe—side effect profiles compared to benzodiazepines.

Suvorexant is FDA approved for insomnia, characterised by difficulties with sleep onset and/or sleep maintenance.

Prescribing of nonbenzodiazepines has seen a general increase after their initial release on the US market in 1992, from 2.3% in 1993 among individuals with sleep disorders to 13.7% in 2010.

Antipsychotics

The use of antipsychotics for insomnia, while common, isn't recommended as the evidence doesn't demonstrate a benefit and the risk of adverse effects is significant. Concerns regarding side effects is greater in the elderly.

Alternative medicine

Some insomniacs use herbs such as valerian, chamomile, lavender, cannabis, hops, Withania somnifera, and passion-flower. L-ArginineL-aspartate, S-adenosyl-L-homocysteine, and delta sleep-inducing peptide (DSIP) might additionally be helpful in alleviating insomnia. It is unclear if acupuncture is useful.

Prognosis

A survey of 1.1 million residents in the United States found that those that reported sleeping about 7 hours per night had the lowest rates of mortality, whereas those that slept for fewer than 6 hours or more than 8 hours had higher mortality rates. Getting 8.5 or more hours of sleep per night increased the mortality rate by 15%. Severe insomnia – sleeping less than 3.5 hours in women and 4.5 hours in men – is associated with a fifteen percent increase in mortality. Notwithstanding most of the increase in mortality from severe insomnia was discounted after controlling for co-morbid disorders. After controlling for sleep duration and insomnia, use of sleeping pills was additionally found to be associated with an increased mortality rate.

The lowest mortality was seen in individuals who slept between six and a half and seven and a half hours per night. Even sleeping only 4.5 hours per night is associated with quite little increase in mortality. Thus, mild to moderate insomnia for most people is associated with increased longevity and severe insomnia is associated only with a quite small effect on mortality. It is unclear why sleeping longer than 7.5 hours is associated with excess mortality.

Epidemiology

Disability-adjusted life year for insomnia per 100,000 inhabitants in 2004.
  no data
  less than 25
  25–30.25
  30.25–36
  36–41.5
  41.5–47
  47–52.5
  52.5–58
  58–63.5
  63.5–69
  69–74.5
  74.5–80
  more than 80

Between ten percent and thirty percent of adults have insomnia at any given point in time and up to half of people have insomnia in a given year. About six percent of people have insomnia that isn't due to another problem and lasts for more than a month. People over the age of 65 are affected more often than younger people. Females are more often affected than males. Insomnia is forty percent more common in women than in men.

There are higher rates of insomnia reported among university students compared to the general population.

Society and culture

The topic of insomnia is discussed in a large number of cultural contexts.

The word insomnia is from Latin: in + somnus "without sleep" and -ia as nominalizingsuffix.