What Factors Lead to Insomnia?

By Brandon Peters, MD

It’s 1 a.m. again. You can’t sleep. You have been lying awake for hours. Just when sleep seems within your grasp, you are cruelly pulled back to wakefulness. How are you going to function tomorrow? Why can’t you get to sleep? If you find yourself struggling to fall and stay asleep, learn how you can master the factors that lead to your insomnia and get the rest that you need.

Sleep Depends on Drive and Circadian Rhythms

There are certain factors working in your favor that should help you get to sleep at night. When these are corrupted, however, they may quickly start working against you and lead to insomnia. To better understand how this may occur, it is important to first consider the patterns that lead to sleep and why some people can’t sleep at night.

Sleep depends on two independent processes: sleep drive and circadian rhythm. Sleep drive is the desire for sleep that builds gradually during wakefulness. Put simply, the longer you are awake, the more you want to sleep. This is thought to be due to the gradual accumulation of a chemical within the brain called adenosine, one of the neurotransmitters. Sleep is a time to clear adenosine away, and when you are awake it piles up and leads to increased sleepiness. A poorly timed nap during the day will diffuse the chemical and diminish your ability to sleep at night.

The other factor that determines when (and whether) you can sleep is something called the circadian rhythm. Our bodies respond to the natural daily patterns of light and darkness, linking certain biological processes to these rhythms. One of these processes is sleep.

There are certain factors that affect these circadian rhythms. Melatonin is a hormone that has a key role in regulating sleep patterns. Exposure to light exerts the most powerful influence, however. Taken together, the circadian rhythm encourages the specific timing of sleep and wakefulness. Sleep that is attempted counter to our natural desires is often ineffectual. Moreover, a prolonged shift in the timing of sleep may represent a circadian rhythm sleep disorder.

What Factors Cause Insomnia?

Insomnia is defined as difficulty falling asleep, staying asleep, or sleep that is simply not refreshing. How this happens is best understood by considering a theoretical model of what causes someone to have insomnia. According to Dr. Arthur Spielman’s model, there seem to be three considerations, summarized as predisposing, provocative, and precipitating factors.

First, it seems that some people have a predisposition towards insomnia. The threshold for developing insomnia will vary for each person. Believe it or not, there are people who rarely or never develop trouble sleeping at night. On the other hand, some people may be unlucky and are simply predisposed to have insomnia. This likely relates to genetic factors (insomnia often runs in families), age, sex (more often women), substance use, and other medical and psychiatric conditions.

Insomnia may also be attributed to an increased alerting signal. This relates to the sympathetic nervous system, which is responsible for the so-called “fight or flight” response. Some people may have an increased sympathetic drive, meaning they are primed to respond to an external threat. This signal can keep you awake during the day – but it also keeps insomniacs up at night. Some have described this as being “tired but wired”.

Even though you might have a predisposition towards insomnia, it has to be triggered. These triggers are called provocative factors. Insomnia might occur transiently and be secondary to stress, a cup of coffee, or an uncomfortable sleep environment. About 25 percent of people cannot identify the trigger for their insomnia. If you hadn’t encountered the trigger, however, you might continue to sleep without difficulty. Instead, you find yourself in the throes of acute insomnia. In time, this may resolve. But sometimes it doesn’t.

The final components that transform a passing difficulty sleeping into chronic insomnia are the precipitating factors. These are the elements that perpetuate the difficulty sleeping. These can best be understood by considering an example.

Let’s imagine that you lie awake several hours in the middle of the night, a common occurrence in insomnia. You recognize that you need 8 hours of sleep and by lying awake you are cutting into this time. You decide to start going to bed 2 hours earlier to compensate. This helps some, but now that you are going to bed extra early it is taking you more time to fall asleep. As you lie awake more of the night, your frustration increases and you compound your initial insomnia.

There are a variety of choices that might perpetuate your insomnia. Some people choose to limit their daytime activities because of sleepiness. This avoidance may reduce your physical activity. Since you are less tired, you may be less able to sleep. You may start working on your computer in bed to make the most of your time spent awake. This light and activity may worsen your ability to sleep. In addition, you may start napping during the day to get some sleep, and this could undermine your sleep drive and ability to sleep at night. All told, perpetuating factors are going to prolong your battle with insomnia.

How to Get to Sleep

Now that you understand the factors that might lead you to have difficulty sleeping at night, you no doubt wonder how you are going to get to sleep. In general, you can follow these simple rules:

1.    Build up your sleep drive through sleep restriction.

Work to make yourself tired by limiting your time in bed with sleep restriction. Avoid naps that may diminish your ability to sleep at night. Do not sleep in divided periods. If you find you cannot sleep, do not allow yourself prolonged wakefulness in bed, but observe stimulus control. These interventions can increase the quality of your sleep.

2. Respect your circadian rhythm, and sleep at the right time for you.

Acknowledge your body’s desired timing of sleep. If you are a night owl, don’t go to bed too early and lie awake. If you wake early, allow yourself adequate sleep time by going to bed early as well. There are ways to adjust the timing of your sleep, but start by sleeping when your body desires.

3.    Avoid triggers that can precipitate insomnia.

If you can identify the causes of your insomnia, do your best to avoid these triggers. Start by eliminating caffeine, especially after noon. Consider other ways that you may be ruining your sleep. Don’t forget about treating other sleep disorders, as these can also trigger difficulty falling or staying asleep.

4.    For those with chronic insomnia, seek professional help.

Finally, if you are suffering from chronic insomnia, lasting more than 3 months, you may need to seek professional help. When insomnia becomes prolonged, it is necessary to pursue other interventions. Sleeping pills may help in the short term, but other treatments are preferred for chronic insomnia. It can be very helpful to address the beliefs, thoughts, and feelings that surround your insomnia with a treatment called cognitive behavioral therapy.

If you suffer from insomnia, start by considering the factors that underlie your difficulty. Then talk with your doctor and if appropriate ask for a referral to a sleep specialist.

Sources:

Kryger, MH et al. "Principles and Practice of Sleep Medicine." ExpertConsult, 5th edition, 2011.

Spielman AJ, Caruso LS, Glovinsky PB. A behavioral perspective on insomnia treatment. Psychiatr Clin North Am. 1987;10(4):541-553.

Why Does Insomnia Happen?

By Brandon Peters, MD

There are few things more frustrating than an inability to sleep. Insomnia may undermine your night’s rest, leading to important daytime consequences. Why does insomnia happen? Learn about the factors that may lead to an inability to sleep at night and consider what you might do about them.

Insomnia is defined as the inability to fall or stay asleep or sleep that is unrefreshing in the absence of another sleep disorder (such as sleep apnea). It is the most common of all the various sleep disorders, and it may be a significant problem in about 1 in 4 people. Nearly everyone has experienced some degree of insomnia, even if only transiently, but why does this occur?

Spielman’s theoretical model of insomnia underpins our current understanding of the disorder. This theory suggests that three things contribute to the development of chronic insomnia, including: predisposing, precipitating, and perpetuating factors.

Predisposition: The Threshold for Insomnia

It is believed that everyone has the capacity to develop difficult sleeping at night. This predisposition is likely genetically determined. Some of the contributions to it likely include our individual circadian rhythm, homeostatic sleep drive, and level of arousal. The circadian rhythm directs the timing of our sleep, and it may be either advanced or delayed in some people. The homeostatic sleep drive is dependent on the build of sleep-promoting chemicals, including the compound called adenosine. The longer we stay awake, the sleepier we become, due in part to these chemicals. Finally, the baseline level of arousal also is factored in. Some people are more “wired” – also likely due to varying levels of neurotransmitters that promote wakefulness – and this may make sleep disruption more likely.

The predisposition towards insomnia can be thought of as a threshold. Below the threshold at which insomnia will develop, you sleep fine. Given the proper scenario, however, and the balance tips toward sleep disruption. The things that provoke the development of insomnia are known as the precipitating factors.

The Precipitating Factors for Insomnia

What might cause insomnia? There will be some variability in what provokes insomnia in you. Triggers for insomnia may not be the same for every person. Something that is particularly disruptive to your sleep may have no effect on someone else’s. This varying sensitivity is normal, and it shouldn’t be a source of additional distress.

Some of the most common triggers for insomnia include stress, mood disorders, pain, substance use, and poor sleep environment. Stress of every imaginable type is highly likely to make it difficult to sleep. The night before a big examination or presentation at work may be fitful. Major life events such as moving, the loss of a job, relationship problems including divorce, or the death of a close friend or relative may also lead to insomnia. If these problems lead to anxiety or depression, the risk of insomnia may be compounded.

There are other causes of insomnia as well. In particular, chronic medical conditions, especially those that cause pain, may disrupt sleep. Sleep is usually an anesthetic state, in which pain is not sensed, but nevertheless pain can make it hard to fall asleep. There are certain substances that may contribute to difficulty falling or staying asleep as well. The most common, caffeine, is notorious for sleep disruption. Nicotine is another stimulating substance that disrupts sleep. Alcohol may cause drowsiness initially, but when it starts to wear off, sleep becomes fragmented. Other medications and drugs can also undermine sleep.

Finally, the sleep environment can also make it hard to sleep. If your bedroom is too warm or too cold, too bright, or too noisy, sleep may be fleeting. An uncomfortable bed, or none at all, may also cause insomnia. If someone is snoring nearby, or a baby cries out to be fed, sleep becomes light and fragmented. Studies have also shown that environmental noise, such as may be present in a busy city, can also disrupt sleep.

It should also be noted that working against your natural ability to sleep can also cause insomnia. If you try to sleep at a time that your body expects you to be awake (contradicting your circadian rhythm), you will likely lie awake. If you took a prolonged nap in the afternoon, your desire for sleep will be diminished due to a weakened sleep drive. In addition, if you are wound up after a fight with your spouse (with increased arousal), insomnia will likewise result.

Perpetuating an Inability to Sleep

Once your threshold for insomnia has been crossed, incited by one of the precipitating factors, you will find yourself lying awake at night. This may quickly pass, as occurs in acute insomnia. If you had insomnia due to an examination that has come and gone, for example, the difficulty sleeping goes away with it. However, there are scenarios where insomnia will persist, and unintentional behavioral or cognitive changes may actually make things worse.

If the precipitating factor has not resolved, it is very likely that it will continue to disrupt your sleep. It is possible to adapt to some of these triggers, depending on the nature of the disruption, but this may not always happen. Therefore, it can be important to identify the cause of the insomnia and try to resolve it. This will require a careful self-assessment of the factors that are important to your situation.

Unfortunately, some triggers are not easily remedied. It may require a tincture of time to grieve a death. A mood disorder may require medication or psychotherapy. A new baby may take months to sleep through the night. Focus on what you have control over, and avoid making things worse.

Many people with insomnia unintentionally make their insomnia more sustained. Several bad nights of sleep (or dozens, for that matter) may lead you to change your pattern of sleep. This can be particularly true if you find yourself waking and lying awake in the night. You may think, “I am not sleeping well, so I am going to go to bed earlier to try to get enough sleep.” By extending your time in bed, you have introduced a new problem: you are now going to bed earlier than your body wants you to. If your body says you will get sleepy at 11 PM, but you crawl into bed at 9 PM, guess what happens? You will now have trouble falling asleep as well.

There can be a lot of emotions and thoughts that become associated with insomnia. Chronic insomnia is deeply frustrating. Feelings of distress, hopelessness, inadequacy, and failure become part of the scenario. People who sleep well do not wake in the morning and assess how well they slept. Insomniacs often do. Sleep becomes a focus in insomnia, and when it does, it becomes a challenge. There can also be an element of catastrophization, in which the worst possible scenario is imagined during the periods of wakefulness: “If I don’t get enough sleep, I’m going to get fired.” Many of these thoughts and feelings must be defused, and cognitive behavioral therapy for insomnia (CBTI) can be very helpful in this regard.

It is clear that insomnia can happen for multiple reasons, as detailed above. Everyone has a specific threshold at which insomnia will develop. The precipitating factors will vary for each person, but there are common triggers related to stress, mood, pain, and substance use. Acute insomnia becomes chronic when behaviors, thoughts, and emotions change surrounding sleep. If you find yourself stuck in the pattern of insomnia, it can be helpful to speak to a sleep specialist to begin to make changes that can correct the problem. Insomnia can be treated effectively, so reach out to get the help that you need.

Source:

Kryger, MH et al. “Principles and Practice of Sleep Medicine.” Elsevier, 5th edition. 2011.