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Wednesday, May 17, 2017

Sleep Science – The Mechanisms Behind Insomnia

 Everyone is prone to a sleepless night or two, brought on by excitement or stress. However, for some, lack of sleep can last for weeks, sometimes months. Sustained sleep-deprivation is something that is estimated to affect between 20% and 50% of adults. Much work has gone into researching not only how to cure insomnia but also what the mechanisms are that cause it.

The 3 P's of Insomnia

A popular explanation for this sleep disorder looks at three key factors – predisposition, precipitation, and perpetuation. Advocates of the 3-P Model believe that insomniacs have certain characteristics, such as being naturally anxious or being perfectionists, that make them more susceptible to sleep problems. This predisposition, combined with a precipitating event, such as a death of a loved one or job stress, can affect sleep resulting in a period of acute insomnia (short-term sleep loss). The third facet of this model is that anxiety about, and poor attitudes towards, sleep will perpetuate the symptoms of insomnia. This is because, the more uneasiness a sufferer feels about falling asleep, the more active their brain will be, resulting in them actually staying awake for longer.


The Cognitive Processes of Sleeplessness

This idea of perceptions of how one will sleep feeds into the Cognitive Model of insomnia, an idea put forward over ten years ago. The simple concept is that those suffering from insomnia worry about their sleep and what will happen if they don't get enough. These thoughts actually trigger emotional stress and brain activity which causes the individual to search themselves and their surroundings for factors that could interrupt their sleep, such as noise, light, or discomfort. In the process of focussing on these things they actually bring themselves back into a state of full wakefulness, as the brain isn't allowed to wind down. By actively focussing on the act of falling sleep, insomniacs delay it, by maintaining the brain in a state of awareness.

The Brain Chemistry of Insomniacs

Related to the Cognitive Model, but taking a more in depth stance, the Neurocognitive Model of sleep deprivation explores how brain activity may differ between those with regular sleeping patterns and those without. Scientists have observed that those suffering from acute insomnia actually have higher levels of electrical activity in the brain than those who don't suffer sleep problems. The result of this could be that insomnia sufferers may have higher sensory or information processing activity during times when those with regular sleeping patterns don't. This could have drastic effects on a person's ability to fall asleep, as they are more aware of what is happening around them.



The role physiological factors has been more thoroughly researched, as it has come to be believed that insomniacs may have innate characteristics that affect how easily their sleep is disrupted by both external and psychological factors. Elevated levels of brain metabolism have been observed in studies of insomniacs, making it harder for them to switch off at night. Furthermore, it has been seen that patients with insomnia secrete less melatonin at night, the hormone responsible for making us feel tired. This, combined with the observed increased levels of norepinephrine, a hormone similar to adrenaline, in insomniacs have the debilitating effect of making it much harder to fall asleep.


Thankfully, as insomnia becomes better understood, more techniques and medical interventions are being developed to cure it.

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