title: The insomnia with short sleep duration phenotype: an update on it's importance for health and prevention.
abstract: OBJECTIVE
  It was first proposed in the late 1990s that objective markers of sleep disturbance could serve as an index of the biological severity of insomnia. In 2013, a heuristic model of two insomnia phenotypes based on objective sleep duration was proposed. Herein, we review the studies conducted in the past 3 years on the insomnia with short sleep duration phenotype and its implications for a clinical research agenda.
  
  
  RESULTS
  Studies have shown that insomnia with objective short sleep duration is associated with physiologic hyperarousal and cardiometabolic and neurocognitive morbidity, whereas insomnia with normal sleep duration is not. Both insomnia phenotypes are associated with psychiatric morbidity albeit through different psychobiological mechanisms. Novel recent studies have included occupational outcomes, developmental approaches, at-home objective sleep testing, diagnostic accuracy measures, and response to cognitive-behavioral treatment.
  
  
  CONCLUSIONS
  Accumulating evidence in the past years has continued to support that insomnia with short sleep duration is a more severe phenotype of the disorder associated with physiologic changes, significant morbidity and mortality and, potentially, a differential response to treatment.
authors.affiliation: Sleep Research and Treatment Center, Penn State Milton S. Hershey Medical Center, Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, USA.
authors.forename: Julio
authors.initials: J
authors.lastname: Fernandez-Mendoza
mesh_terms: D006801:Humans; D007319:Sleep Initiation and Maintenance Disorders / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000503:physiopathology* / Q000628:therapy