title: Insomnia Phenotypes Based on Objective Sleep Duration in Adolescents: Depression Risk and Differential Behavioral Profiles.
abstract: Based on previous studies on the role of objective sleep duration in predicting morbidity in individuals with insomnia, we examined the role of objective sleep duration in differentiating behavioral profiles in adolescents with insomnia symptoms. Adolescents from the Penn State Child Cohort (n= 397, ages 12-23, 54.7% male) underwent a nine-hour polysomnography (PSG), clinical history, physical examination and psychometric testing, including the Child or Adult Behavior Checklist and Pediatric Behavior Scale. Insomnia symptoms were defined as a self-report of difficulty falling and/or staying asleep and objective "short" sleep duration as a PSG total sleep time ≤7 h. A significant interaction showed that objective short sleep duration modified the association of insomnia symptoms with internalizing problems. Consistently, adolescents with insomnia symptoms and short sleep duration were characterized by depression, rumination, mood dysregulation and social isolation, while adolescents with insomnia symptoms and normal sleep duration were characterized by rule-breaking and aggressive behaviors and, to a lesser extent, rumination. These findings indicate that objective sleep duration is useful in differentiating behavioral profiles among adolescents with insomnia symptoms. The insomnia with objective short sleep duration phenotype is associated with an increased risk of depression earlier in the lifespan than previously believed.
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. jfernandezmendoza@hmc.psu.edu.
authors.forename: Julio
authors.initials: J
authors.lastname: Fernandez-Mendoza
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. scalhoun@psu.edu.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Calhoun
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. avgontzas@hmc.psu.edu.
authors.forename: Alexandros N
authors.initials: AN
authors.lastname: Vgontzas
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. yunli@hmc.psu.edu.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. jgaines1@hmc.psu.edu.
authors.forename: Jordan
authors.initials: J
authors.lastname: Gaines
authors.affiliation: Public Health Sciences, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. dliao@phs.psu.edu.
authors.forename: Duanping
authors.initials: D
authors.lastname: Liao
authors.affiliation: Sleep Research & Treatment Center, Penn State Milton S. Hershey Medical Center, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA. ebixler@hmc.psu.edu.
authors.forename: Edward O
authors.initials: EO
authors.lastname: Bixler
keywords: adolescents; depression; externalizing behaviors; insomnia; internalizing behaviors; objective sleep duration; phenotypes; rumination