Sleep - What Sleep Is, How Sleep Works, Why Do We Sleep, How Sleep Can Go Wrong


Insomnia can result in a whole host of different symptoms and complications, both short-term and long-term (image from Wikipedia)
Insomnia can result in a whole host of different symptoms and complications, both short-term and long-term (image from Wikipedia)
Insomnia is a general term referring to any difficulty in falling asleep or staying asleep, such that the sufferer is still tired, unrefreshed and unrested on waking. Left untreated, it may lead to irritability, memory problems, depression, anxiety, and, in the longer term, to an increased risk of accidents, heart disease, hypertension, diabetes, immune system problems, etc. A recent study by British researchers has indicated that the normal working over 700 separate genes may be affected by the reduced sleep times associated with insomnia, with potentially severe implications over an extended period.

It is a very common complaint - indeed, the most commonly diagnosed sleep disorder - affecting some 30% to 50% of the general population according to some estimates, with about 10% of the population suffering from long-standing or chronic insomnia. It can occur at any age, but is most common in the elderly. It is also generally more common among women than men.

Insomnia is often a symptom or side-effect of another disease or complaint (such as hyperthyroidism, congestive heart failure, chronic obstructive pulmonary disease, dementia, pain-related conditions, or other underlying sleep disorders) rather than a disorder in itself, in which case it is known as secondary insomnia. However, where the insomnia symptoms are not due to any specific physical or mental imbalance and have no obvious other cause, it is referred to as primary insomnia.

Insomnia can also be classified according to its general causes: psychophysiological insomnia (the classic type, arising from to a variety of psychological and behavioural stressors and/or environmental and situational causes); paradoxical insomnia (genuine complaints of little or no sleep that are not corroborated by objective evidence of actual sleep disturbances); and idiopathic insomnia (persistent insomnia, usually beginning in childhood, which is unrelated to psychosocial stressors or medical disorders).

Insomnia may also be classed depending on its regularity and persistence: transient insomnia (insomnia that persists for just a few days, usually following a stressful event or excessive use of stimulants like caffeine or nicotine); episodic (short-term) insomnia (insomnia symptoms that last up to three weeks, interspersed with periods or more or less normal sleep); or chronic (persistent) insomnia (ongoing insomnia symptoms that recur at least two days a week for at least a month).

Finally, insomnia is sometimes categorized according to the part of the sleep period which is disrupted: sleep-onset (initial) insomnia (difficulty getting to sleep in the first place); sleep-maintenance (middle) insomnia (difficulty staying asleep or getting back to sleep once woken); or terminal (late) insomnia (waking up too early in the morning).

Insomnia may have one or more of several causes, including (but not limited to) stress, heartburn or acid reflux, bed-wetting, a poor sleep environment, aches and pains from injuries or illnesses, an inconsistent sleep schedule, excessive exercise or food just before bedtime, or the effects of medications, alcohol, tobacco, caffeine, etc. It is often not understood that caffeine, for example, has a “half-life” of about five hours, so that, even five hours after a cup of coffee or a cola, half of the caffeine still remains active in the body, and as much as a quarter is still there even ten hours later.

Stress is the major cause of short-term insomnia
Stress is the major cause of short-term insomnia

The number one cause of episodic or transient insomnia is stress and anxiety, whether from school- or job-related pressures, family or marriage problems, serious illness or death in the family, etc. Middle-aged men in particular have been shown to exhibit increased sensitivity to arousal-producing stress hormones, such as corticotropin-releasing hormone and cortisol. But, if short-term insomnia is not managed properly, it can morph into a long-term problem, persisting long after the original stress has passed. Most insomniacs tend to be anxiety-prone by nature, and this may predispose them to worry more about sleep. Stress and anxiety about difficulties in sleeping may in itself be enough to perpetuate the insomnia, in a kind of vicious circle (sometimes referred to as conditioned insomnia).

At the extreme end of the scale, there is a very rare genetic sleep disorder called fatal familial insomnia (FFI), which appears in a handful of families in late adulthood, and which is in fact quite as fatal as the name suggests. In FFI, malformed proteins called prions attack the thalamus, an organ in the brain that plays a major role in regulating sleep. The sufferer gradually completely loses the ability to sleep, first the ability to nap and then the ability to sleep at night. Hallucinations soon follow, then rapid weight loss and dementia, and finally complete unresponsiveness. Within a year of striking, the disease causes death.

The first step in the treatment of insomnia should always be to identify and remove contributing factors to the sleep problem. Usually, simple behavioural changes and improved sleep hygiene (i.e. eliminating some of the common causes) are sufficient to treat the problem, and increased exercise (although not too close to bedtime), relaxation therapy and white noise are also often beneficial. In some cases, though, more active interventions may be called for, such as sleep restriction therapy, stimulus control therapy, paradoxical therapy, cognitive-behavioural therapy, etc.

Bright light therapy is often combined with other treatments for insomnia (image from Wikipedia)
Bright light therapy is often combined with other treatments for insomnia (image from Wikipedia)

Sleep restriction therapy is an effective, if rather gruelling, treatment for insomnia. It involves setting a consistent wake-up time every morning, regardless of the amount of sleep achieved, and very gradually increasing sleep time, over a period of weeks or months, from an initial achievable low level. Bright light therapy in the morning is also often incorporated. Stimulus control therapy (also called the “10-minute rule”) is also an effective insomnia treatment technique, which imposes the strict rule that an individual has just ten minutes to fall asleep and, if sleep is not achieved in that time, they must get up, go into another room and relax for a while (for example, by doing something boring and mindless), and only return to bed gain when they feel sleepy.

Paradoxical therapy, which asks the insomniac to do the exact opposite of trying to fall asleep, has proven to be a surprisingly effective therapeutic approach to conquering insomnia. By instructing a patient to continue the symptomatic behaviour instead of stopping it, this forces them to confront the problem and to make a deliberate decision on how to proceed, which in some cases may serve to eliminate any subconscious resistance to treatment. Cognitive-behavioural therapy, which effectively combines most of these interventions into an organized whole and attempts to change patients’ dysfunctional attitudes towards sleep, has yielded good long-term results among chronic insomniacs.

Too many insomniacs, however, rely on sedatives and other sleep medications, despite the fact that most of these have unfortunate side-effects and also carry the added risk of dependence, and some studies have thrown serious doubts on their effectiveness anyway. The most common medications for insomnia include different kinds of hypnotics such as benzodiazepines (e.g. temazepam, flunitrazepam, triazolam, etc) and non-benzodiazepines (e.g. zolpidem, zopiclone, eszopiclone, zaleplon, etc), as well as antidepressants (e.g. doxepin, trazodone), antihistamines (e.g. diphenhydramine, doxylamine), melatonin (e.g. ramelteon), etc.