title: Psychological features of subjects with idiopathic environmental intolerance.
abstract: OBJECTIVE
  Idiopathic environmental intolerance (IEI) is associated with unexplained symptoms attributed to non-noxious levels of environmental substances. Clinically, some of the symptoms of IEI overlap with those of panic disorder (PD). We have recently reported a link between IEI and panic responses to a single inhalation of 35% carbon dioxide (CO(2)), a reliable panic induction challenge. This study assessed depression, stress, anxiety, and agoraphobic symptoms among IEI subjects from our previous study versus healthy controls.
  
  
  METHODS
  Thirty-six IEI and 37 control subjects with no preexisting psychiatric history were compared on self-report psychological questionnaires.
  
  
  RESULTS
  IEI subjects scored significantly higher than controls on the Agoraphobic Cognitions Questionnaire (ACQ), Depression Anxiety Stress Scales (DASS), and Mobility Inventory for Agoraphobia (MI) (Student's t, P<.05).
  
  
  CONCLUSIONS
  IEI subjects represent a group with morbidity significantly higher than a control population but less than what would be expected for a clinical psychiatric population.
authors.affiliation: Gage Occupational and Environmental Health Unit, University of Toronto, 223 College Street, Toronto, Ontario, Canada M5T 1R4.
authors.forename: N P
authors.initials: NP
authors.lastname: Poonai
authors.forename: M M
authors.initials: MM
authors.lastname: Antony
authors.forename: K E
authors.initials: KE
authors.lastname: Binkley
authors.forename: P
authors.initials: P
authors.lastname: Stenn
authors.forename: R P
authors.initials: RP
authors.lastname: Swinson
authors.forename: P
authors.initials: P
authors.lastname: Corey
authors.forename: F S
authors.initials: FS
authors.lastname: Silverman
authors.forename: S M
authors.initials: SM
authors.lastname: Tarlo
mesh_terms: D000328:Adult; D000379:Agoraphobia / Q000150:complications*; D001007:Anxiety / Q000150:complications*; D002245:Carbon Dioxide; D016022:Case-Control Studies; D003863:Depression / Q000150:complications*; D018876:Environmental Illness / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D016584:Panic Disorder / Q000139:chemically induced / Q000523:psychology*; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index; D013315:Stress, Psychological / Q000150:complications*
chemical_list: D002245:Carbon Dioxide