title: Sleep requirement: long sleepers, short sleepers, variable sleepers, and insomniacs.
mesh_terms: D006801:Humans; D010551:Personality; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000628:therapy; D013315:Stress, Psychological; D013997:Time Factors