title: Factor analysis of subjectively reported sleep habits, and the nature of insomnia.
abstract: Factor analysis was performed on variables used to describe subjectively the sleep habits of three groups of subjects--male patients, female patients, and medical students. Similarities in the six factors from each analysis indicate the existence of dimensions of variation which are common to normal sleep habits and insomnia.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D004325:Dreams; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012647:Self-Assessment; D012737:Sex Factors; D012890:Sleep; D007319:Sleep Initiation and Maintenance Disorders / Q000175:diagnosis*; D012893:Sleep Wake Disorders / Q000188:drug therapy; D013337:Students, Medical; D011795:Surveys and Questionnaires; D013997:Time Factors; D014851:Wakefulness
chemical_list: D006993:Hypnotics and Sedatives