title: Psychological Distress and Physiological Reactivity During In Vivo Exposure in People With Aviophobia.
abstract: OBJECTIVE
  Exposure is regarded to be a crucial component of therapies for phobias. According to emotional processing theory, the success of exposure therapy is predicted by activation of subjective and physiological fear responses and their within-session habituation and between-session adaptation. This study tested this prediction for aviophobia.
  
  
  METHODS
  Seventy-nine participants following a highly standardized treatment program for aviophobia provided self-reported and physiological (heart rate, respiratory sinus arrhythmia and pre-ejection period) measurements of fear activation, within-session habituation, and between-session adaptation during exposure to flight-related stimuli, a flight simulator, and during two real flights. Multiple regression analyses were conducted to examine whether these measurements predicted therapy outcome up to 3 years after finishing therapy, including number of flights flown in this period.
  
  
  RESULTS
  Both subjective and physiological arousal measurements indicated strong fear activation and large within-session habituation and between-session adaptation during exposure. Flight anxiety measures showed large improvements up to 3 years after treatment (η between 0.72 and 0.91). Lower self-reported anxiety during flight exposure was associated with lower flight anxiety after exposure (R = 0.15) and more flights flown (R = 0.14). Within-flight habituation or between-session adaptation of self-reported anxiety had no relationship with treatment outcome. Within-flight habituation of HR reactivity (R = 0.10) and respiratory sinus arrhythmia reactivity (R = 0.11) was associated with lower flight anxiety directly after the flight, but not on flight anxiety 3 years after finishing therapy or on long-term flying behavior.
  
  
  CONCLUSIONS
  The results provide only weak support for emotional processing theory. Low self-reported anxiety during in vivo flight exposure was the best predictor of successful long-term therapy outcome.
authors.affiliation: From the VALK Foundation (Busscher), Leiden, the Netherlands; Institute of Psychology (Busscher, Spinhoven), Leiden University, Leiden, the Netherlands; Department of Psychiatry (Spinhoven), Leiden University Medical Center, Leiden, the Netherlands; and Department of Biological Psychology and EMGO+ Institute (de Geus), VU University & VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: Bert
authors.initials: B
authors.lastname: Busscher
authors.forename: Philip
authors.initials: P
authors.lastname: Spinhoven
authors.forename: Eco J C
authors.initials: EJ
authors.lastname: de Geus
mesh_terms: D000328:Adult; D000401:Aircraft; D001143:Arousal / Q000502:physiology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007171:Implosive Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010698:Phobic Disorders / Q000503:physiopathology*; D065809:Respiratory Sinus Arrhythmia / Q000502:physiology; D057566:Self Report; D013315:Stress, Psychological / Q000503:physiopathology*; D055815:Young Adult