Insomnia (Hammerschlag, 2017) – Is insomnia genetic?

woman sleeping

Nebula Genomics DNA Report for Insomnia

Is insomnia genetic? We created a DNA report based on a study that attempted to answer this question. Below you can see a SAMPLE DNA report. To get your personalized DNA report, purchase our Whole Genome Sequencing!

Sample report on insomnia from Nebula Genomics
Sample variants on insomnia from Nebula Genomics
To learn more about how Nebula Genomics reports genetic variants in the table above, check out the Nebula Research Library Tutorial.
This information has been updated to reflect recent scientific research as of October 2021

What is Insomnia? (Part 1 of Is insomnia genetic?)

The term insomnia refers to a disorder in which an individual has trouble sleeping, either through difficulty falling or staying asleep. These are normally the basis of the first two questions a healthcare professional asks to diagnose the condition. Causes can be external (such as noise at night, excessively bright street lighting), behavioral, or biological factors.

The lack of restful sleep impairs mental performance at work and school. It can also lead to the worsening or recurrence of diseases in the medium or long term. In addition, the condition is believed to be a significant factor in many car crashes and results in a wide range of injuries and disabilities. Lack of sleep has also been found a culprit in major events such as the Challenger and Chernobyl disasters. Most people with the condition will notice daytime drowsiness, low energy, irritability, and a depressed mood.

Man lying awake in bed
Depressed man suffering from insomnia lying in bed. Penn State. Flickr.

In many cases, the condition will be the result of a different disease or illness. By treating the underlying condition, patients tend to see their insomnia improve as well. If a sleep disorder is diagnosed, behavioral and cognitive therapy are usually the first treatment options available. While sleep medications are available, their effectiveness may not be worth the risk of injuries or addictions associated with long-term use of these drugs.

Is Insomnia Genetic?

Common insomnia is a combination of genetic and environmental factors. The condition tends to be common in family members, suggesting an inherited component. Overall, many genes are thought to be linked to insomnia to various degrees. A research study published in February 2019 in Nature Genetics analyzed data that identified 57 genetic regions thought to influence the condition. The lead on the genome-wide association study was Jacqueline Lane, a researcher at the Center for Genomic Medicine at Massachusetts General Hospital in Boston. 

Fatal familial insomnia (FFI) is a rare genetic degenerative brain disorder. Insomnia associated with this condition starts mild but becomes progressively worse until physical and mental capacities deteriorate. Most patients notice onset around 40-60 years of age, and the disease is fatal in 6-36 months. This disease affects the prion proteins in the thalamus, a brain region that controls the sleep-wake cycle. 

As a whole, prion diseases are rare. In total, all prion diseases are thought to affect about one person per million people in the general population per year. Thus, this condition is extremely rare.

FFI is caused when the PRNP gene does not work correctly. This gene regulates the production of the human prion protein. Alterations in this gene lead to the generation of abnormally-shaped prion protein, which is toxic to the body. In FFI, the abnormal prions build up primarily within the brain’s thalamus. This leads to the progressive loss of nerve cells (neurons). The mutation is inherited in an autosomal dominant pattern meaning that an individual needs to inherit only one copy of the mutation from either parent to have the condition. It can also happen sporadically, without an inherited component. But, again, either of these conditions is extremely rare in the general population.

Current Research on Insomnia [Updated October 2021]

While it is clear that specific behavioral patterns could trigger insomnia, it is also believed to have genetic predispositions. Research in this field is scarce, but fortunately, a number of studies have provided useful results on these questions.

Following research in 2018 summarized by Science Daily, researchers identified specific genes that seem to trigger sleep problems and linked the AUTS2 as one of them. The AUTS2 is also responsible for insomnia and other psychiatric disorders such as depression and physical conditions such as type 2 diabetes. The study found that insomnia did have a genetic leaning, but genes are not the only conditions responsible for it.

A 2018 research published in Molecular Psychiatry revealed that insomnia and sleep disorders are genetically related. The research was championed by Murray Stein of the University of California San Diego and the VA San Diego Healthcare System. The focus sample was large respondents across the United States.

Stein and his research team performed genome-wide association studies (GWAS). A large range of data was analyzed, including DNA samples obtained from more than 33,000 soldiers participating in the Army Study To Assess Risk and Resilience in Servicemembers (STARRS). Also, data from soldiers of European, African, and Latino descent were grouped separately to identify the influence of specific ancestral lineages. Stein and his colleagues also compared their results with two recent studies that used data from the UK Biobank. 

From the study, Stein and his team concluded that insomnia had a partially heritable basis. Among participants of European descent, there was additionally a genetic tie between sleeplessness and major depression. 

Stein and his team linked insomnia to the occurrence of specific variants on chromosome 7. In people of European descent, there were also differences in chromosome 9. 

According to a review published in 2012, the heritability of sleep patterns has been shown in twin studies. Also, there was promising evidence that sleep electroencephalogram patterns offer a unique genetic fingerprint that may assist in identifying genes involved in the regulation of sleep. The study showed that recent genetic advances showed that Hypocretin/ Orexin System plays a major role in sleep disorders.

Citing insomnia specifically in a string of sleep disorders, the study also stated that the neuro-genetic condition, FFI, is predominantly due to mutation in codon D178N of the prion protein (PrP) gene. The gene is said to be the cause of special thalamic nuclei degeneration.

Epidemiology (Part 4 of Is insomnia genetic?)

In the United States, anywhere from 20 percent to 40 percent of adults report symptoms of insomnia at some point in a given year. Out of all adults, 9.5% report short-term insomnia. However, the condition was found to continue in 40% to 70% of patients for as long as four years. 

According to the American Insomnia Survey in 2008-2009, more than 50% of adults had difficulty sleeping, and 22.1% met the diagnostic criteria for insomnia. In addition, the condition appears to be more common in women than in men. It is also more prevalent in the elderly population, individuals with low socioeconomic status, and those with poor health or low quality of life, suggesting that social and societal stress may be involved. 

Short sleep (defined as getting less than 7 hours of sleep within 24 hours) is most common in the eastern portion of the United States.

Symptoms (Part 5 of Is insomnia genetic?)

Insomnia is a common disorder with the main symptoms being the inability to fall and stay asleep. 

There are two types of insomnia: short-term and chronic. Short-term forms of the condition last only a few days or weeks and usually are stress-related. When it becomes chronic, occurring at least three nights a week and lasting for three months or longer, the sleep disorder may be associated with an underlying condition.

Chronic insomnia symptoms include:

  • Difficulty falling asleep and/or waking up too early
  • Difficulty returning to sleep
  • Feeling tired/fatigued during the daytime
  • Irritability or depressed mood
  • Problems with concentration or memory

Not getting enough sleep is linked to several common chronic conditions such as type 2 diabetes, heart disease, coronary artery disease, obesity, and depression.  

Although symptoms persist in some patients, others may experience it as a waxing and waning condition.

Causes (Part 6 of Is insomnia genetic?)

The cause of your condition depends on the type. 

Acute insomnia, which only lasts for a short amount of time, is normally attributed to certain life events.  Stress (job, relationship, financial, etc.) is usually the most common cause of poor sleep. Taking care of your mental health is often a key aspect of improving sleep. Other risk factors in the short term include experiencing a traumatic event, changes to sleep habits or environment, physical pain, jet lag, and certain medications.

Chronic insomnia, which lasts longer than three months, usually has an underlying condition. In some cases, when no known cause can be found, it is referred to as primary insomnia. Oftentimes, a patient will experience secondary insomnia, which can be caused by:

  • Chronic pain such as occurs with arthritis or back pain
  • Psychological issues, such as anxiety or depression
  • Substance use
  • Sleep apnea
  • Diabetes
Lying awake
Lying awake at night due to stress is common. Judit Klein. Flickr.

Risk factors

Some people may be at higher risk of developing insomnia than others. Specifically, patients who engage in certain lifestyles or who suffer from certain disorders are more prone to sleep problems, including those with:

  • High levels of stress
  • Emotional disorders, such as depression or distress related to a life event
  • Lower income
  • Traveling to different time zones
  • Sedentary lifestyle
  • Changes in work hours or working night shifts
  • Obesity
  • Cardiovascular disease
  • Menopause

Diagnosis (Part 7 of Is insomnia genetic?)

To diagnose insomnia that is not part of an underlying medical condition, your doctor will often start by asking you questions regarding your health history, family history, sleep patterns, and environment. Questionnaires that focus on things like when you go to bed, how long it takes you to fall asleep, and whether you feel rested are also helpful. 

A physical exam will be used to look for signs of other health problems. Listening to the heart and lungs is often crucial in diagnosing sleep apnea. Sometimes, a blood test will be recommended to diagnose certain health conditions like a thyroid disorder, especially if you have other symptoms. 

Oftentimes, your doctor might recommend a review of your sleep habits by completing a sleep diary for 1-2 weeks. Templates for sleep diaries can be found online. Usually, you will take note of when you fall asleep, wake up, how drowsy you feel throughout the day, when you drink caffeine and alcohol, and when you exercise. This record can help your doctor determine if certain habits are affecting your sleep.

Someone writing in a sleep diary
Keeping a sleep diary can help diagnose problem areas. Shane Adams. Flickr.

If there is no underlying cause and your doctor suspects you have a sleep disorder such as sleep apnea, narcolepsy, a circadian rhythm disorder, or restless leg syndrome, they may recommend a sleep study. In this case, you will spend the night in a sleep center, where doctors can monitor and record your sleeping. The measurements include brain waves, breathing, heartbeat, eye movements, and body movements.

There are certain sleep centers all over the United States that have specialists who can help with diagnosis.

Treatment (Part 8 of Is insomnia genetic?)

The first approach to treat insomnia is usually a change to sleeping habits and other lifestyle aspects that affect sleep such as stress and medications. If those treatments are not effective, you may be referred to cognitive behavioral therapy, sleep medications, or both to help get a good night’s sleep.

Cognitive behavioral therapy for insomnia

Cognitive behavioral therapy for insomnia (CBT-I) helps you control or eliminate negative thoughts, worries, and actions that keep you awake. It can help you realign how you think about certain stressful things in your life to promote good sleep. It also allows you to take action to develop good sleep habits that can lead to a better night’s rest.

There are several strategies to CBT-I. You may be asked to try all or some of them. One strategy is stimulus control therapy, in which you are coached to remove factors that prevent sleep. An example would be setting up a consistent sleep schedule. Relaxation techniques are another common approach in which muscle relaxation, biofeedback, hypnosis, meditation, and breathing exercises help physically prepare the body for rest.

Sleep restriction is another technique that may be used. This may be recommended for patients who spend a lot of time awake in bed, trying to fall asleep. In this approach, you will be asked to restrict sleep to certain times in a way that causes you to be slightly sleep-deprived and thus increase your drive to sleep in bed. Then, once you spend most of your time in bed sleeping, you progressively add more time. For example, if you are trying to sleep 8 hours a night but only getting 5 hours, you would start by adjusting your bedtime routine to 5 hours and 30 minutes in bed. 

Medications

Prescription medications can be used to help patients fall, stay asleep, or both. However, this option comes with several side effects including daytime grogginess and increasing the risk of falling. They can also be habit-forming, so you should be sure to follow the instructions provided carefully. In most cases, they will be prescribed for only a few weeks. Several studies have looked for new therapeutic targets to better help those with sleep trouble. As of now, few of these studies have led to new drugs.

Some people use nonprescription drugs that contain antihistamines to induce sleep. Patients should obtain medical advice before using these medications as sleep aids since this is not their intended use. They can cause daytime sleepiness, dizziness, confusion, cognitive decline, and difficulty urinating.

If you liked this article, you should check out our other posts in the Nebula Research Library!