title: Do asthma patients with panic disorder really have worse asthma? A comparison of physiological and psychological responses to a methacholine challenge.
abstract: BACKGROUND
  Panic disorder (PD) has been linked to worse asthma outcomes. Some suggest that asthmatics with PD have worse underlying asthma; others argue that worse outcomes are a result of their tendency to over-report symptoms. This study aimed to measure physiological and psychological responses to a simulated asthma attack (methacholine challenge test: MCT) in asthmatics with and without PD.
  
  
  METHODS
  Asthmatics with (n = 19) and without (n = 20) PD were recruited to undergo a MCT. Patients completed subjective symptom questionnaires (Panic Symptom Scale, Borg Scale) before and after a MCT. Physiological measures including heart rate (HR), and systolic and diastolic blood pressure (SBP/DBP) were also recorded.
  
  
  RESULTS
  Analyses, adjusting for age and sex, revealed no difference in methacholine concentration required to induce a 20% drop in forced expiratory volume in one second (FEV1: F = 0.21, p = .652). However, PD patients reported worse subjective symptoms, including greater ratings of dyspnea (F = 8.81, p = .006) and anxiety (F = 9.44, p = .004), although they exhibited lower levels of physiological arousal (i.e., HR, SBP/DBP). An interaction effect also indicated that PD, relative to non-PD, patients reported more panic symptoms post-MCT (F = 5.05, p = .031).
  
  
  CONCLUSIONS
  Asthmatics with PD report higher levels of subjective distress, despite exhibiting lower levels of physiological arousal, with no evidence of greater airway responsiveness. Results suggest that worse outcomes in PD patients may be more likely due to a catastrophization of bodily symptoms, rather than worse underlying asthma. Interventions designed to educate patients on how to distinguish and manage anxiety in the context of asthma are needed.
authors.affiliation: Montreal Behavioural Medicine Centre, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin West, Montréal, Québec, H4J 1C5, Canada; Department of Psychology, University of Quebec at Montreal (UQAM), P.O. Box 8888, Succursale Center-Ville, Montreal, Quebec, H3C 3P8, Canada.
authors.forename: Maxine
authors.initials: M
authors.lastname: Boudreau
authors.affiliation: Montreal Behavioural Medicine Centre, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin West, Montréal, Québec, H4J 1C5, Canada; Department of Psychology, University of Quebec at Montreal (UQAM), P.O. Box 8888, Succursale Center-Ville, Montreal, Quebec, H3C 3P8, Canada; Université de Montréal, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.
authors.forename: Kim L
authors.initials: KL
authors.lastname: Lavoie
authors.affiliation: Université de Montréal, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.
authors.forename: André
authors.initials: A
authors.lastname: Cartier
authors.affiliation: Montreal Behavioural Medicine Centre, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin West, Montréal, Québec, H4J 1C5, Canada.
authors.forename: Barbara
authors.initials: B
authors.lastname: Trutshnigg
authors.affiliation: Montreal Behavioural Medicine Centre, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin West, Montréal, Québec, H4J 1C5, Canada; Department of Exercise Science, Concordia University, 7141 Sherbrooke St. West, Montreal, Quebec, H4B 1R6, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Morizio
authors.affiliation: Université de Montréal, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.
authors.forename: Catherine
authors.initials: C
authors.lastname: Lemière
authors.affiliation: Montreal Behavioural Medicine Centre, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin West, Montréal, Québec, H4J 1C5, Canada; Department of Exercise Science, Concordia University, 7141 Sherbrooke St. West, Montreal, Quebec, H4B 1R6, Canada. Electronic address: simon.bacon@concordia.ca.
authors.forename: Simon L
authors.initials: SL
authors.lastname: Bacon
mesh_terms: D000328:Adult; D000368:Aged; D001007:Anxiety / Q000523:psychology; D001249:Asthma / Q000503:physiopathology* / Q000523:psychology; D001794:Blood Pressure / Q000187:drug effects; D001985:Bronchial Provocation Tests / Q000379:methods* / Q000523:psychology; D004417:Dyspnea / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage*; D008875:Middle Aged; D016584:Panic Disorder / Q000503:physiopathology* / Q000523:psychology*; D012720:Severity of Illness Index
chemical_list: D016210:Methacholine Chloride
keywords: Anxiety; Asthma; Asthma severity; Methacholine challenge test; Panic disorder