Genetics may play a role in children and adolescents that suffer from insomnia.
Philip R. Gehrman, PhD, of the Penn Sleep Center at the University of Pennsylvania in Philadelphia, and colleagues, examined 1,412 pairs of twins between the ages of 8 and 18. Of that number, 739 were identical pairs, 672 were fraternal, and in one pair, the twin type was not known.
The twins were studied at four different time points. Average age during those periods were 8, 10, 15 and 15 years old.
“Clinically significant insomnia” was moderately heritable at all stages of the study, the researchers reported in the journal Sleep. Genetic factors contributed between 33 and 38% of the insomnia ratings at the first two stages of the study, when participants’ average age was between 8 and 10.
Heritability of insomnia was between 14 and 24% at the final two time points, when the average age of participants was between 14 and 15 years. The variance in insomnia ratings was attributed to the non-shared environment.
“Insomnia in youth is moderately related to genetic factors, but the specific genetic factors may change with age,” Gehrman said in a statement. “We were most surprised by the fact that the genetic factors were not stable over time, so the influence of genes depends on the developmental stage of the child.”
A new study of twins suggests that insomnia in childhood and adolescence is partially explained by genetic factors.
Results show that clinically significant insomnia was moderately heritable at all stages of the longitudinal study. Genetic factors contributed to 33 to 38% of the insomnia ratings at the first two stages of the study, when participants had an average age of 8 to 10 years. The heritability of insomnia was 14 to 24% at the third and fourth follow-up points, when the average age of participants was 14 to 15 years. The remaining source of variance in the insomnia ratings was the non-shared environment, with no influence of shared, family-wide factors.