Psychological features of subjects with idiopathic environmental intolerance

Abstract

Objectives: Idiopathic environmental intolerance (IEI) is associated with unexplained symptoms attributed to nonnoxious 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.