Written on November 28, 2022 by Theresa Vuskovich, DMD. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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Have you ever wondered whether your sleepless nights are the result of genetics or late-night phone scrolling? If so, this article is here to break down the science of insomnia and inheritance. You will learn about the types of insomnia, the genetic and environmental factors contributing to insomnia, and some treatment options.
Insomnia is a sleep-wake disorder characterized by difficulty falling asleep and staying asleep, resulting in impairment during the daytime . In general, adults need between 7-9 hours of sleep. Insomnia is classified in the following manner :
If you are struggling with any of these symptoms, you are not alone. 33% to 50% of the adult population experiences insomnia symptoms [3,6,15]. However, only 10% meet the criteria for an insomnia diagnosis, according to the American Psychiatric Association [1,15].
Nevertheless, insomnia remains one of the most prevalent mental disorders in the United States and can increase your risk for other diseases, such as high blood pressure and depression [11,12]. Insomnia has a bidirectional relationship with other conditions, meaning diseases can cause insomnia symptoms, and insomnia can cause diseases. Having long-term insomnia symptoms can increase your risk of disease .
Insomnia is classified as chronic or short . A chronic insomnia diagnosis is defined as insomnia symptoms occurring at least three times a week for three months, and a short insomnia diagnosis is defined as insomnia symptoms occurring for at least one month but not more than three months . You are at an increased risk for chronic and short insomnia if you meet any of the following criteria [1,15]:
While these factors increase your risk for insomnia, genetics also plays a significant role. Having gained some basic understanding of insomnia, let's examine whether genetics or environmental factors cause insomnia.
Insomnia is a result of genetics and environment. Insomnia is hereditary, and studies show heritability contributes between 38% and 59% of your lifetime risk [7,10,11]. However, environmental factors, such as sleep hygiene practices, can play a much greater role in the development of insomnia than genetics. Let's first explore the genetics of insomnia and later return to the environmental causes of insomnia.
As a quick review, a hereditary trait can be genetically passed from parents to their children. Perhaps you remember the Punnett square from biology class. The Punnett square determines the probability of a child inheriting a specific trait. Unfortunately, the Punnett square does not fully explain how a gene is inherited.
A phenotype (physical trait such as eye color) is usually not created by a single gene but results from several genes and complex interactions between them . Many rare diseases are the exception and are often the result of a single gene mutation. For example, fatal familial insomnia (FFI) is a rare disease in which a mutation to a single gene, PRNP, leads to the inability to sleep and other nervous system problems . FFI is extremely rare, and treatment does not currently exist .
Researchers use genome-wide association studies (GWAS) to find multiple genes that may influence an individual's development of insomnia [6,7,16,17]. Currently, researchers have identified numerous genes that may impact your likelihood of developing insomnia, as well as genes affecting the characteristics of your sleep [8,14]. For instance, your chronotype, your body's inclination to wake up early or late, is partly due to genetics .
Now let's discuss environmental factors and epigenetics, the interaction between your genes and your environment. Your environment, including UV and chemical exposures, can alter your gene's function and, ultimately, your phenotype. Identifying how the environment affects genes is difficult. Thus, researchers are conducting more studies to determine how environmental factors impact genes that cause insomnia. In addition to epigenetics, your physical sleeping environment and bedtime routine also impact your ability to sleep.
A recent study of over 800 individuals and twins found many environmental factors you can control to improve how you feel in the morning. The study found an individual's ability to wake up after sleeping is not only affected by genetics but also by exercising the day before and eating carbohydrates for breakfast . The results suggest genes alone are not responsible for sleep and wakefulness .
While insomnia does not have a cure, you have many treatment options to help you improve your ability to sleep [7,15]. Identifying what is disrupting your sleep is a good place to start if you are having trouble sleeping. If you cannot improve your insomnia symptoms, here are some treatment options [1,7,13,15]:
These are just a few options available to improve your insomnia symptoms. Consult your healthcare provider to determine what is the best option for you.