HERITABILITY OF INSOMNIA SYMPTOMS IN YOUTH
Heritability of Insomnia Symptoms in Youth and Their Relationship to Depression and Anxiety
Philip R. Gehrman, PhD1,3; Lisa J. Meltzer, PhD2; Melisa Moore, PhD3; Allan I. Pack, MBChB, PhD3,4; Michael L. Perlis, PhD1; Lindon J. Eaves, PhD5; Judy L. Silberg, PhD5
1Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; 2Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania and The Children's Hospital of Philadelphia, Philadelphia, PA; 3Center for Sleep and Respiratory Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; 4Division of Sleep Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA; 5Virginia Commonwealth University School of Medicine, Richmond, VA
Insomnia is a highly prevalent sleep disorder yet little is known about the role of genetic factors in its pathophysiology. The aim of this study was to examine the relative contributions of genetic and environmental factors in explaining variability in insomnia symptoms.
Traditional twin design.
Academic medical center.
1412 twin pairs aged 8-16 years (48.8% MZ, 47.2% DZ, 4.0% indeterminate).
Measurements and Results:
Ratings of insomnia symptoms, depression, and overanxious disorder were made by trained interviewers based on DSM-III-R criteria. ACE models were conducted using Mx statistical software. Insomnia symptoms were prevalent in this sample based both on parental (6.6%) and youth (19.5%) reports. The overall heritability of insomnia symptoms was modest (30.7%), with the remaining variance attributed to unique environmental effects. There was no evidence of sex differences in the prevalence of insomnia symptoms or in the contribution of genetic and environmental effects. In multivariate models, there was support for insomnia-specific unique environmental effects over and above overlapping effects with depression and overanxious disorder, but no evidence for insomnia-specific genetic effects.
Genetic factors play a modest role in the etiology of insomnia symptoms in 8-16 year-olds. These effects overlap with the genetics of depression and overanxious disorder. Further work is needed to determine which genes confer risk for all three disorders.
Gehrman PR; Meltzer LJ; Moore M; Pack AI; Perlis ML; Eaves LJ; Silberg JL. Heritability of insomnia symptoms in youth and their relationship to depression and anxiety. SLEEP 2011;34(12):1641-1646.