title: Central and peripheral chemoreflexes in panic disorder.
abstract: Klein (Arch Gen Psychiatry, 50, 1993, 306-317) has suggested that panic disorder patients have a false suffocation alarm that may be associated with a lowered threshold for carbon dioxide detection. We compared the thresholds and sensitivities of the central and peripheral chemoreflexes between panic disorder patients and age- and sex-matched healthy volunteers to test this aspect of the hypothesis. We used a modified version of Read's rebreathing technique in 11 panic disorder patients and 10 healthy volunteers to examine the peripheral and central chemoreflex characteristics in these two populations. Subjects were examined during three rebreathing tests: training, hyperoxic (central chemoreflex alone) and hypoxic (combined central and peripheral chemoreflex). Panic symptoms were retrospectively assessed between groups using a DSM-IV derived Panic Symptom Scale. Comparisons of panic disorder patients with agoraphobia and healthy volunteers showed no significant differences in sensitivities or thresholds. Klein's hypothesis is not supported by these data. If a false suffocation alarm exists, its triggering may not be implemented within the respiratory chemoreflexes.
authors.affiliation: Anxiety Disorders Clinic, Centre for Addiction and Mental Health-Clarke Division, 250 College Street, Toronto, Ontario, Canada M5T 1R8. martin_katzman@camh.net
authors.forename: Martin A
authors.initials: MA
authors.lastname: Katzman
authors.forename: Lukasz
authors.initials: L
authors.lastname: Struzik
authors.forename: Nishka
authors.initials: N
authors.lastname: Vijay
authors.forename: Aimee
authors.initials: A
authors.lastname: Coonerty-Femiano
authors.forename: Safraaz
authors.initials: S
authors.lastname: Mahamed
authors.forename: James
authors.initials: J
authors.lastname: Duffin
mesh_terms: D000328:Adult; D001237:Asphyxia / Q000523:psychology; D002245:Carbon Dioxide / Q000378:metabolism; D002628:Chemoreceptor Cells / Q000503:physiopathology*; D004056:Differential Threshold / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism; D016584:Panic Disorder / Q000209:etiology / Q000503:physiopathology*; D012021:Reflex, Abnormal / Q000502:physiology*; D012119:Respiration
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen