Investigators found that stress was likely to be the most modifiable risk factor.
A recent study found that poorer mental health status and being female when entering puberty may be risk factors for the etiology of insomnia. Investigators noted a lack of longitudinal studies of insomnia predictors in children and adolescents, which rendered them unable to draw firm conclusions.
A total of 6 papers were included in the systematic review, with data included from 6419 children in 5 countries (the United States, New Zealand, Norway, China, and Japan). Included participants were between the ages of 6-18 years at follow-up, which was performed between 1-9 years after the first assessment in each longitudinal community study.
When evaluating predictors, investigator Lars Wichstrøm, PhD, professor, department of psychology, Norwegian University of Science and Technology, and colleagues created 6 groups: sociodemographic factors, mental health factors, somatic health factors, parent- and family-related factors, school factors, and lifestyle factors.
Of the 4 studies investigators, 2 found that women were more likely than men to develop insomnia later on, while 2 others that were conducted in southeast Asia—that notably did not consider daytime impairment—did not find the same association. In these 4 studies, it was found that other sociodemographic factors were unrelated to the development of future insomnia, except for parental education, which was found to be risk factor for persistent chronic insomnia.
In terms of family, parental, school, and lifestyle factors, investigators concluded that some studies identified stress in the family system or school as a risk factor for insomnia, also noting that stress may be the most modifiable risk factor. School stress was found to be the stronger predictor of insomnia in a study that performed an odds ratio adjusted for potential confounders, and another study found that mobile phone use was also a risk factor that forecasted insomnia.
“Although it seems reasonable that family distress may produce disruptive emotions or rumination/worry in children and adolescents, which, in turn, may lead to difficulties initiating and maintaining sleep, the results summarized here are far from conclusive regarding the role of these factors in the etiology of insomnia,” Wichstrøm et al wrote. “Furthermore, school stress was the strongest predictor of insomnia in terms of odds ratios in a study that adjusted for several potential confounders. School stress has been reported elsewhere to increase when entering adolescence. Thus, school may contribute to stress, which, consistent with stress-reactivity thinking, may trigger insomnia, especially if combined with vulnerability towards reactivity (eg, difficult temperament and neuroticism).
Depression was also found to be a risk factor for insomnia at the disorder and symptom levels, according to consistent findings. Investigators note that mental and somatic health indicators did not generally overlap in the included studies, but results were incompatible when they did. Additionally, 1 meta-analysis had limited data to support depression as a risk factor for insomnia, but found it was predictor for broader definitions of sleep disturbance in adolescence.
The systematic search was limited, as insomnia criteria vary across different diagnostic manuals and few longitudinal studies exist on this topic. Skewed rater disagreement may also have affected results, with screeners including certain papers and disregarding others.
“We call for more high-quality prospective studies with a well-defined operationalization of insomnia that can improve our understanding of its predictors in children and adolescents in community populations.,” Wichstrøm et al wrote. In accordance with a psycho-bio-behavioral model of insomnia future research should also investigate more comprehensive etiological models of diagnosable insomnia that include factors from different levels of influence across childhood. The field would probably also advance if consensus were reached on how to operationalize insomnia across studies. Also, including a minimum of common predictors across studies would enable researchers to be better positioned to identify relevant predictors, which may guide preventive as well as treatment efforts.”