title: Incidence of psychiatric disorders after extended residence in Antarctica.
abstract: OBJECTIVE
  The incidence of psychiatric disorders and depressive symptoms was examined in a cohort of American men and women who spent an austral winter at two different research stations in Antarctica to determine whether extended residence of nonindigenous inhabitants in a polar region is associated with psychiatric morbidity.
  
  
  METHODS
  Debriefings interviews with 220 men and 93 women were conducted by 3 psychiatrists and 1 clinical psychologist at McMurdo Station and South Pole Station at the end of the austral winter between 1994 and 1997. Crewmembers were assigned a DSM-IV diagnosis if they satisfied diagnostic criteria. Debriefed crewmembers also completed the Structured Interview Guide for the Hamilton Depression Inventory-Seasonal Affective Disorders version (SIGH-SAD).
  
  
  RESULTS
  Thirty-nine (12.5%) crewmembers presented with symptoms that met the criteria for one or more DSM-IV disorders. After weighting the prevalence to account for the low participation rate of civilian personnel, the incidence of DSM-IV disorders was 5.2%. Mood disorders were the most common diagnoses, accounting for 30.2% of all diagnoses, followed by adjustment disorders (27.9%), sleep-related disorders (20.9%), personality disorders (11.6%), and substance-related disorders (9.3%). Depressive symptoms as measured by the SAD-SIGH were significantly associated with female gender, military occupation, station, year of expedition, and DSM-IV diagnosis.
  
  
  CONCLUSIONS
  Differences in the distribution of symptoms and diagnoses by demographic and expedition characteristics suggests that the social environment may be a more powerful determinant than the physical environment of psychiatric disorders in a polar region.
authors.affiliation: Department of Family and Preventive Medicine, University of California, San Diego, La Jolla 92093-0807, USA. Lpalinkas@ucsd.edu
authors.forename: Lawrence A
authors.initials: LA
authors.lastname: Palinkas
authors.forename: Frederic
authors.initials: F
authors.lastname: Glogower
authors.forename: Mark
authors.initials: M
authors.lastname: Dembert
authors.forename: Kendall
authors.initials: K
authors.lastname: Hansen
authors.forename: Robert
authors.initials: R
authors.lastname: Smullen
mesh_terms: D000328:Adult; D000864:Antarctic Regions; D003081:Cold Climate; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D012108:Research Personnel; D012621:Seasons