Is insomnia inherited or learned?
Results of a twin study provide answers into the heritability or environmental influences related to insomnia.
Insomnia may be inherited
Linda, aged 29 years, is a patient who I follow for insomnia. She started having issues with her sleep during her pre-teen years. Linda has done everything I have asked of her regarding proper sleep hygiene.
She tries to avoid sleep aids but finds herself lying awake for hours, hoping for a few hours of rest. Nothing seems to help. She has reported that her mother and her brother also have insomnia. She believes it is something she has inherited from her mother, and new evidence published in SLEEP suggests this may be true.
Is insomnia something inherited from family or is it a learned behavior? This question comes up for sleep providers often. Arguably, children learn poor sleep habits from their parents, but maybe children's poor sleep habits are related to the insomnia issues that their parents experience.
Insomnia is defined as difficulty falling asleep, staying asleep or waking early and feeling unrefreshed from sleep. According to published reports, the prevalence of insomnia can range from 4% to 41% in children and adolescence.
Insomnia can affect children's young brains and mental development. There is some thought that specific genes are responsible for insomnia and a life changing event in childhood may trigger those genes and cause insomnia.
Nicole L. Barclay, MD, of Northumbria University in the United Kingdom, and colleagues concluded that insomnia is moderately heritable. The investigators conducted a longitudinal twin study with both monozygotic (n=739 and dizygotic (n=672) twins over four points of time throughout their childhood and adolescence.
The participants were enrolled in the Virginia Twin Study of Adolescent Behavioral Development, a cohort of twins aged eight to 17 years. Twin studies are important because they help us look at genetic and environmental influences.
Insomnia issues in early childhood were thought to be more behavioral in nature. Small children often have poor sleep hygiene because their sleep is usually governed by parents. So, children may be sent to bed on parents' schedules instead of a schedule more beneficial for children.
In adolescence, parents are less likely to determine children's bedtime or are unaware of when the teen is actually sleeping. Therefore, in adolescence, insomnia can improve when the teen is allowed to sleep with times that are more true to their natural circadian rhythm.
However, taking away the behavioral or environmental factors, some children continued with insomnia issues throughout the study in line with what we see in the adult population, which lends to the suggestion of heritability.
Those children who had insomnia at age 10 years were more likely to continue with insomnia through adolescence. This raises the question as to whether changes in the body at that age might raise the potential of insomnia throughout life.
There is definitely more to be learned about insomnia and the causes. New studies are appearing frequently, so hopefully I'll have more to report in future blogs.
What is your feeling? Is insomnia behavioral, influenced by your environment, or is it inherited?
Sharon M. O'Brien, MPAS, PA-C, is a practicing clinician with an interest is helping patients understand the importance of sleep hygiene and the impact of sleep on health.
- Barclay NL, Gehrman PR, Gregory AM, Eaves LJ, Silberg JL. SLEEP. 2015; 38(1):109–118.