Insomnia is a general term used to describe the perception that the amount or quality of sleep one experiences is inadequate, despite that the fact that the opportunity for adequate sleep exists. The problems can range from having difficulty falling asleep, being too easily disrupted with multiple awakenings, or early morning awakenings with an inability to fall back asleep. It is important to note which specific set of symptoms are expressed, as this may not only indicate the cause but helps to refine treatment. As such insomnia isn’t really a disease at all, but a symptom that can be related to numerous disorders including anxiety, depression, and chronic pain, or may be the result of a variety of medications or drugs such as alcohol (which can cause night-time wakening from rebound hypoglycemia) and psychostimulants such as amphetamines. Insomnia, however, is associated with a variety of complaints experienced during the daytime, including an impaired ability to concentrate, poor memory, difficulty coping with minor stressors, and a decreased ability to maintain functional relationships.
There are three basic types of insomnia that can be found, classified on the basis of the duration of the complaint:
- Transient insomnia: lasting no more than one week, usually caused by acute stress such as a new job, a project deadline, or an upcoming exam. In many cases it is a pattern that repeats itself with new or similar stressors.
- Short-term insomnia: lasting for a period of one to six months, usually associated with a persistent stressful situational, such as the chronic illness or death of a loved one, or environmental factors such as an uncomfortable bed, room temperature, and extraneous noise.
- Chronic insomnia: lasting more than six months; associated with a wide variety of physical and mental health disorders.
As mentioned, the specific symptoms of insomnia can indicate possible causes. For example, depression is most commonly associated with early morning awakening and an inability to fall back asleep. Schizophrenia and bipolar mania are often are associated with difficulty falling asleep, whereas anxiety disorders are associated with difficulty falling asleep and maintaining sleep. The drugs taken to treat these conditions can also affect the quality and nature of sleep. Another possible cause of chronic insomnia is obstructive sleep apnea, which promotes awakening due to difficulty breathing. In some cases the causes of insomnia may relate to restless leg syndrome (RLS) or periodic limb movement disorder (PLMD), a sleep disorder characterized by spasmodic movements of the limbs that wake one up. Shift workers frequently complain of insomnia, due to a fundamental disruption of normal circadian cycles that are guided by the interplay of light and melatonin secretion in the brain. If no cause can be ascertained, the condition is referred to as primary insomnia, and is a fairly rare idiopathic condition that often manifests early in childhood.
It is important to note that insomnia is a subjective experience. Although most people require a minimum of eight hours sleep to feel refreshed upon awakening, some people appear to have a decreased requirement for sleep, and appear to be able to function on less sleep than others. Elderly people often complain of difficulties sleeping, and while it is more difficult for them to experience sustained sleep, their sleep requirements are about the same as for an adolescent. In this way, it is often necessary for older folks to take naps during the day, ideally in the mid-to-late afternoon, before dinner.
The nature of sleep
Sleep is a term used to describe an altered state of consciousness or partial unconsciousness from which an individual can be aroused. Normal sleep consists of two components, non-rapid eye movement (NREM) and rapid eye movement (REM). NREM consists of four distinct stages that can measured by an EEG:
- Stage one: the transition between wakefulness and sleep, usually lasting between 1-7 minutes. The subject’s eyes are closed and may have fleeting thoughts. The α-waves that mark normal consciousness gradually diminish. Subjects that are roused from this state usually feel that they have not been sleeping.
- Stage two: the first stage of true sleep, in which the subject is more difficult to arouse. Fragments of dreams may be experienced, and the eyes can be seen to role from side to side. EEG readings demonstrate the characteristic sleep spindle, a burst of sharply pointed waves that occur in the 12-14 Hz range, lasting 1-2 seconds.
- Stage three: a period of moderately deep sleep, occurring about 20 minutes after falling asleep, in which the subject is difficult to arouse. There is a reduction in body temperature and blood pressure, and the EEG shows a mixture of sleep spindles and larger, lower frequency waves.
- Stage four: the period of deepest sleep, in which large, slow delta waves dominate the EEG reading, with a reduction brain metabolism, body temperature, and muscle tone. The subject is most difficult to arouse in this state, and if sleep-walking or bedwetting occurs, usually does so only during this stage of NREM sleep.
The movement from stages one to four typically occurs in less than an hour. These different phases of NREM sleep are interspersed with progressively longer periods of REM sleep during a normal 8 hour sleeping cycle, characterized by the movement the eyes rolling back and forth under closed eyelids. The brain waves observed in REM sleep are small and irregular and resemble the waking state. The blood pressure can increase drastically and the pulse rate and breathing may become irregular, which is why REM sleep is associated with an increased risk of a myocardial infarction. Although the subject’s large muscle groups are literally paralyzed, the small muscles in the face, toes and fingers may twitch, and both men and women can experience vascular engorgement of the penis and clitoris even when the content of the dream isn’t sexual. The presence of penile erection in men suffering from erectile dysfunction indicates that the problem is more likely related to psychogenic factors.
The first episode of REM sleep usually occurs before the second hour of sleep and lasts only 10-20 minutes, followed by an interval on NREM sleep. REM and NREM sleep then alternate throughout the sleep period about every 90 minutes. The alternating period of REM sleep, however, gradually lengthens, such that the last period of REM sleep can last upwards of 50 minutes. In total REM sleep accounts for about 90-120 minutes of a normal sleep cycle. In an infant, however, REM sleep can account for up to 50% of the total sleep period, in contrast to about 35% for toddlers, and 25% for adults, with the percentage declining with age. Sleep spindles seen in stages two and three of NREM sleep usually begin by about the 3rd month of life. Although the purpose of sleep and REM sleep specifically isn’t clear, it is thought that the high percentage of REM sleep in the young is related to proper neuronal development.
There are different parts of the brain that appear to regulate NREM and REM sleep, with neurons in the preoptic region of the hypothalamus, the basal forebrain and medulla oblongata regulating NREM sleep, and the neurons in the pons and midbrain activating and inhibiting REM sleep. The sleep spindles specifically are thought to arise in the thalamus. One of the more important chemicals thought to play a role in sleep is adenosine which accumulates when high levels of ATP are catabolized. Adenosine binds to specific (adenosine) A1 receptors in the brain, inhibiting cholinergic neurons in the reticular activating system (RAS) that promote arousal. This is the neuropharmacological basis of the stimulatory effects of methylxanthines such as caffeine, which bind to A1 receptors and prevent adenosine from binding, thereby inhibiting sleep.
The purpose of sleep
Despite observing and defining the sleep cycle for more than a century, science has been hard pressed to come up with a reason for sleep. A multitude of theories have been put forward, many of which contradict each other. One hypothesis is that sleep is a homeostatic mechanism used to replenish glycogen stores within the brain (Kong et al 2002). During normal wakefulness, the brain catabolizes glycogen stored and glucose to manufacture ATP, which is used to power neuronal activities in the brain. The result of this is the accumulation of adenosine, which as previously described, inhibits arousal of the RAS. According to this theory, sleep is initiated when adenosine levels are high enough to promote sleep (Benington and Heller 1995). As this process is theorized to occur only during NREM sleep, a question arises as to what the purpose of REM sleep is. In 1994, Benington and Heller suggested that REM is a homeostatic mechanism to induce another cycle of NREM restorative sleep. Following this, the research began to suggest that sleep is essential for memory consolidation, in which newly encoded memories are redistributed to other neuronal networks to serve as long-term memory storage. The process of memory consolidation appears to take place during slow-wave sleep (SWS) rather than rapid eye movement (REM) sleep. SWS appears to help consolidate memories that concern future plans, and helps to enhance memory retrieval (Vorster and Born 2014; Born and Wilhem 2012).
Beyond restoring energy reserves and promoting memory, sleep also serves to promote the detoxification of the brain. During wakefulness, the brain burns glucose as a fuel, and in the process, free radicals are generated that must be quenched before causing tissue damage. Likewise, there are other metabolic by-products that are generated during wakefulness, including beta-amyloid protein, which forms the plaques found in the brains of Alzheimer’s patients. To deal with these toxins the brain maintains a glymphatic system consisting of specialized brain cells called glia, which control the flow of CSF through the brain by shrinking or swelling. Experimental research has show that toxins such as beta-amyloid disappear much faster in the brains of mice when they are asleep, suggesting sleep normally clears toxic molecules from the brain (Xie et al 2013).
Interestingly enough, much of the latest thinking on sleep correlates well with the ancient system of Ayurveda and its conception of sleep. In Ayurveda, sleep is associated with kapha dosha, which is heavy and cool in nature. The kapha nature reflects both the “heavy” quality of sleep, e.g. to “fall” or “sink” into sleep, as well as the experience of inertia during sleep; and the “cool” nature of sleep, which relates to a decrease in metabolic activity. According to Ayurveda, an aspect of kapha called tarpaka kapha becomes especially active during sleep, and is said to help consolidate and enhance memory. As tarpaka kapha flows through the brain, it brings nourishment while assisting in the removal of wastes. In particular, sleep is important for the generation and circulation of ojas, the bodily “juice”metabolized from the nutrients we consume, helping to keeps us youthful and refreshed. A lack of sleep results in a diminishment of ojas, which in turn, results in a diminishment of kapha and qualities of heavy and cool, establishing a viscious cycle whereby the ojas required to fall asleep cannot be properly generated. In this case, Ayurveda suggests meditation as an alternative, and in this regard, insomnia can be seen as a calling to develop one’s spiritual nature.
Medical management of insomnia
The medical management of insomnia depends upon the cause, and may include analgesia for patient’s suffering from chronic pain, or the use of specific psychiatric drugs if the insomnia is thought to be secondary to a psychiatric disorder such as depression. Drug therapy for insomnia usually consists of hypnotics such as benzodiazepines (e.g. clonazepam, triazolam, estazolam, flurazepam) and pyrazolopyrimidines (e.g. zaleplon, zolpidem), and tricyclic antidepressants (e.g. amitriptyline, trazodone) if depression is a part of the symptom picture. These drugs are typically advised to be used for only transient and short-term insomnia, although in many cases end up being used on a long term basis, which is essentially a form of addiction. Many of these drugs interfere with the normal sleep cycle, inhibiting both REM and stage 4 NREM sleep, and thus can interfere with the restorative benefits of sleep. Hypnotics with a rapid onset of action, such as zolpidem, zaleplon, and triazolam are used when the patient has difficulty in falling asleep. If the patient has difficulty maintaining sleep, however, a hypnotic with a slower rate of elimination may be prescribed instead, such as temazepam, estazolam, and flurazepam. Although the risk of dependency is stated to be low, hypnotics should be avoided in patients with a history of substance abuse. Rebound insomnia is a fairly common phenomenon when the drugs are withdrawn abruptly.
Beyond specific drug therapies, behavioral therapies are increasingly recognized as a more appropriate treatment for patients with primary insomnia. These consist of:
- Relaxation therapy. In relaxation therapy the patient is taught to recognize and control somatic muscular tension through a series of exercises that consist of first tensing and then relaxing each major muscle group in a systematic way, such as beginning with the feet and working upwards. Guided imagery and meditation can help the patient focus on neutral or pleasant thoughts and feelings instead of the myriad thoughts, concerns and worries that may typically race through their head when trying to get to sleep.
- Biofeedback. Biofeedback is a form of relaxation therapy that can provide the patient with direct information about physiological processes that he or she isn’t typically aware of, such as muscle tension, body temperature, heart rate, and peripheral vasoconstriction. With the usage of a biofeedback device and special sensors attached to the skin, the technique essentially creates an external loop by which the patient can monitor these physiological states and eventually learn to control them. These devices measure physiological changes associated with emotional states such as stress and anxiety, and when physiological patterns associated with these states are sensed, the biofeedback device provides the patient with a signal, such as a colored light or sound. Patients will then try to control the lights or sound by consciously modifying their behavior. Among the different devices, there are three principle types that are commonly available to consumers: the electromyogram, temperature biofeedback, and galvanic skin response. The electromyogram (EMG) measures muscle tension by placing two electrodes on the skin over the muscle to be monitored, such as the frontalis, masseter and trapezius, which are often contracted in states of emotional stress. Temperature biofeedback monitors skin temperature by attaching a sensor to the foot or to middle or small finger of the dominant hand. A decrease in body temperature is correlated with peripheral vasoconstriction that occurs with the ‘fight or flight’ response. Galvanic skin response (GSH) measures electrical conductance in the skin by discharging a small electrical current through the skin, measuring changes in salt and water content. In heightened states of arousal most people will typically sweat, increasing the electrical conductivity of the skin.
- Stimulus control therapy: stimulus control therapy is a technique that attempts to re-associate the bed with sleepiness instead of arousal. This includes: not using the bed for activities such as reading, watching television, eating, or working in bed. It is also important to ensure that the patient lies down only when sleepy, and if they are unable to fall asleep within a 15-20 minutes period, to get out of bed and engage in another activity until he or she feels sleepy.
Holistic treatment of insomnia
While insomnia is similarly recognized as a symptom of an underlying disorder herbalists have traditionally classified insomnia into two basic types: sthenic (‘hot’) and asthenic (‘cold’). Sthenic insomnia, which corresponds to pitta, manifests as irritability, anger, impatience and frustration. In contrast, the asthenic insomnia form, relating to vata dosha, will manifest as anxiety, fear, worry and grief. Thus on the basis of these differences in symptomology, different approaches may be taken to promote a healthy, restful sleep. Where depression or pain is a factor in the condition, these are addressed simultaneously. Quite often the underlying problem of insomnia, especially when it occurs several hours after retiring, is related to hypoglycemia, and thus measures may also be taken to ensure proper control over blood sugar. Another factor to consider is the disruption to normal circadian rhythms through exposure to artificial light sources, including reading lamps and television or computer monitors late at night. Like most mammals humans traditionally awakened with the rising of the sun and retired when it set. This dynamic is still clearly observed in many traditional, ‘primitive’ societies where electricity is not available. Artificial light is a relatively recent artifact of modern civilization, and being exposed to light sources at night could down-regulate melatonin release and thereby promote night-time wakening. From the perspective of Ayurveda, the best time to sleep is when kapha is active, between the hours after sunset and late evening (about 8-10pm). As the night wears on towards midnight pitta becomes active, and if the patient stays awake during this period the fires of the body become very active, activating the mind and even digestion (i.e. a craving for the ‘midnight snack’). Thus the best time to retire is during the kapha period of time to take advantage of the natural lethargy and somnolence that it produces in the body.
- Sthenic insomnia, with heat, palpitations, flushing, and irritability: Motherwort (Leonorus cardiaca), Skullcap (Scutellaria lateriflora), Passionflower (Passiflora incarnata), Bugleweed (Lycopus virginicus), Vervain (Verbena hastata), Limeflower (Tilia cordata), Lemonbalm (Melissa)
- Asthenic insomnia with coldness, anxiety and fear: Valerian (Valeriana officinalis), Pasqueflower (Anenome pulsatilla), Kava (Piper methysticum), Jatamamsi (Nardostachys jatamansi), Ashwagandha (Withania somnifera), Brahmi (Bacopa monnieri)
- Cerebral insomnia, for overthinking, thoughts racing, best taken throughout the day in divided doses e.g. Reishi (Ganoderma lucidum), Ashwagandha (Withania somnifera), Milk Oats (Avena sativa), Lemonbalm (Melissa)
- Non-specific hypnotics (from weak to strong): California Poppy (Eschscholzia californica), Wild Lettuce (Lactuca virosa), Marijuana (Cannabis) (can be stimulant in some), Himalayan Blue Poppy (Meconopsis grandis), Opium Poppy (Papaver somniferum)
- Delayed onset sedatives: Nutmeg (Myristica fragrans), oral Cannabis extracts
- Antispasmodics, to ease muscular tension: Black Cohosh (Cimicifuga racemosa), Kava (Piper methysticum), Jamaican Dogwood (Piscidia erythrina), Nutmeg (Myristica fragrans), Lobelia (Lobelia spp.), Marijuana (Cannabis)
- Flushing and night sweats associated with menopause: Sage (Salvia officinalis), Ushira (Vetivera zizanoides), Nagakeshara (Mesua ferrea), Sandalwood (Santalum album), Wu Wei Zi (Schizandra chinensis), Huang Qi (Astragalus membranaceus), Huang Bi (Phellodendron amurense), Chuan Xiong (Ligustrum wallachi), Shan Zu Yu (Cornus officinalis)
- Stomachics and carminatives, to relieve indigestion and bloating: Fennel (Foeniculum vulgare), Ginger (Zingiber officinalis), Ajwain (Carum copticum), Prickly Ash (Zanthoxylum americanum), Cardamom (Elettaria cardamomum), Dhanya (Coriandrum sativum), Sweet Flag (Acorus calamus), Dang Shen (Codonopsis pilosula)
- Vitamins: B complex, 100-200 mg, taken before 12 pm
- Minerals: magnesium (i.e. for RLS/PLMD, 800 mg each before bed; chromium, to control blood sugars, 200 mcg t.i.d. with meals
- Melatonin: as a sublingual preparation, 0.3 mg – 3 mg 30 minutes before retiring
- γ-Hydroxybutyric acid (GHB): formerly a legal, nutritional supplement, GHB is now considered a date rape drug. It is, however, legally prescribed in its salt form as sodium oxybate for insomnia in narcoleptic patients. More information.
- eat a proper breakfast
- calorie-restricted diets may interfere with sleeping patterns; eat to satiation
- eliminate coffee, methylxanthine containing foods (tea, chocolate) and caffeine-containing medications
- alcohol used as a sedative may cause night-time awakening due to rebound hypoglycemia
- rule out food sensitivities (e.g. cow’s milk, wheat, sugar, food additives and preservatives)
- high carbohydrate diet may promote rebound hypoglycemia
- avoid drinking water or liquid after the evening meal (6-7pm)
- Lavender, Ylang, Bergamot, Vetivert, Jasmine, Rose, Sandalwood
- write thoughts, worries and concerns onto paper or in a journal before bed-time
- implement a meditation regimen before bed and in the morning
- turn the lights down low by about 9 pm, and avoid reading, watching television, or working on the computer afterwards
- practice regular exercise during the day to discharge somatic tension
- warm oil massage with unrefined sesame oil, over the ears, large joints and feet, particularly in the ‘cold’ forms of insomnia, characterized by over-thinking, anxiety and fear
- adjust the room temperature to a comfortable sleeping temperature, typically a few degrees cooler than room temperature
- fresh air while sleeping is important
- for ‘hot’ insomnia, the room may need to be considerably cooler
- for ‘cold’ insomnia, ensure proper bed clothing and even socks to keep warm
- remove extraneous noises as best as possible; encourage treatment for partners that snore