There are a number of things that can keep a person up at night. Some of these things are thankfully rare, such as fatal familial insomnia, a genetic brain disease in which sufferers—about 100 in the two and a half centuries since it was discovered, from 40 families around the world—sleep progressively less over the course of 18 months, ending in delirium and death.
Most insomnia, however, comes from more prosaic causes. It might be neurological problems, such as traumatic brain injury, or mental illnesses, such as depression, anxiety, schizophrenia, bipolar disorder, or others. It might be a physical illness, such as rheumatoid arthritis, or a side effect of medications such as corticosteroids. Excessive caffeine intake, or consumption late in the day, might be the culprit. It might be simple stress.
Unfortunately, insomnia can also cause stress. The vicious cycles are one of the most frustrating aspects of insomnia. Another example: insomnia can exacerbate depression or anxiety disorders. Moreover sleeplessness has a number of undesirable effects on a person’s daytime life. Being tired after being up all night means poor decision making aptitude, lack of concentration, and unhealthy eating habits. If one person in a couple is sleeping badly, and especially if both are, they will be worse at managing conflict within the relationship and will snap at each other more often and more viciously.
Treating insomnia generally focuses on environmental factors. Avoiding light, noise, and excitement late at night. Restricting caffeine and alcohol—which can interfere with sleep cycles—late in the day. Avoiding the bedroom except for sleeping, to strengthen the mental association. Maintaining a regular sleep schedule without naps. Using light to keep the brain’s circadian rhythm on track. Medications can be prescribed, but they can be habit-forming and can cause the patient to become accustomed to using drugs in order to sleep. Additionally, some of these drugs have worrying side effects.
Recently, a Harvard University neurologist proposed another potential solution to the problem, involving an area of the brain stem called the "parafacial zone." This is one of the structures responsible for automatic bodily functions such as breathing. The scientist says it is also responsible for sleep, and suggests targeted insomnia treatments that operate on the region directly may in the future treat insomnia without side effects or addition.