title: Reactivity to 35% carbon dioxide in bulimia nervosa and panic disorder.
abstract: The inhalation of 35% carbon dioxide (CO₂) induces panic and anxiety in people with panic disorder (PD) and in people with various other psychiatric disorders. The anxiogenic effect of CO₂ in people with eating disorders has received sparse attention despite the fact that PD and bulimia nervosa (BN) have several common psychological and neurobiological features. This study compared CO₂-reactivity across three groups of participants: females with BN, females with PD, and female controls without known risk factors for enhanced CO₂-reactivity (e.g., social anxiety disorder, first degree relatives with PD). Reactivity was measured by self-reported ratings of panic symptomatology and subjective anxiety, analyzed as both continuous variables (change from room-air to CO₂) and dichotomous variables (positive versus negative responses to CO₂). Analyses of each outcome measure demonstrated that CO₂-reactivity was similar across the BN and PD groups, and reactivity within each of these two groups was significantly stronger than that in the control group. This is the first study to demonstrate CO₂-hyperreactivity in individuals with BN, supporting the hypothesis that reactivity to this biological paradigm is not specific to PD. Further research would benefit from examining transdiagnostic mechanisms in CO₂-hyperreactivity, such as anxiety sensitivity, which may account for this study's results.
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada.
authors.forename: Andrea
authors.initials: A
authors.lastname: Woznica
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada. Electronic address: kvickers@psych.ryerson.ca.
authors.forename: Kristin
authors.initials: K
authors.lastname: Vickers
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada.
authors.forename: Naomi
authors.initials: N
authors.lastname: Koerner
authors.affiliation: Department of Psychology, Ryerson University, Toronto, Ontario, Canada.
authors.forename: Katie
authors.initials: K
authors.lastname: Fracalanza
mesh_terms: D000280:Administration, Inhalation; D000293:Adolescent; D000328:Adult; D052018:Bulimia Nervosa / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis*; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D006801:Humans; D016584:Panic Disorder / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis*; D010698:Phobic Disorders / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis; D012307:Risk Factors; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide
keywords: Biological challenge; Bulimia nervosa; Carbon dioxide; Panic disorder