Psychological features of subjects with idiopathic environmental intolerance

J Psychosom Res. 2001 Sep;51(3):537-41. doi: 10.1016/s0022-3999(01)00250-1.


Objectives: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Agoraphobia / complications*
  • Anxiety / complications*
  • Carbon Dioxide
  • Case-Control Studies
  • Depression / complications*
  • Environmental Illness / psychology*
  • Female
  • Humans
  • Male
  • Panic Disorder / chemically induced
  • Panic Disorder / psychology*
  • Psychiatric Status Rating Scales
  • Severity of Illness Index
  • Stress, Psychological / complications*


  • Carbon Dioxide