title: Symptom profiles of natural and laboratory panic attacks.
abstract: BACKGROUND
  Little accurate information is available about the symptomatology of real-life panic attacks and about how well they are reproduced by an experimental model such as the 35% CO2 challenge.
  
  
  METHODS
  Real-life panic symptoms were assessed in a group of 67 panic disorder patients, using daily life monitoring. Panic symptoms elicited by a 35% CO2 challenge were assessed in 61 panic disorder patients, and their frequency was compared with the real-life symptoms.
  
  
  RESULTS
  The most frequent real-life symptoms were palpitations, dizziness and trembling. The 35% CO2 challenge reproduced well the majority of real-life symptoms.
  
  
  CONCLUSIONS
  The findings suggest that the 35% CO2 challenge is a marker for spontaneous panic attacks, which are considered the core of panic disorder.
authors.affiliation: 1Department of Psychiatry and Neuropsychology and Vijverdal Academic Anxiety Center, Maastricht University, Maastricht, the Netherlands.
authors.forename: K R J
authors.initials: KR
authors.lastname: Schruers
authors.affiliation: 1Department of Psychiatry and Neuropsychology and Vijverdal Academic Anxiety Center, Maastricht University, Maastricht, the Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: van de Mortel
authors.affiliation: 1Department of Psychiatry and Neuropsychology and Vijverdal Academic Anxiety Center, Maastricht University, Maastricht, the Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Overbeek
authors.affiliation: 1Department of Psychiatry and Neuropsychology and Vijverdal Academic Anxiety Center, Maastricht University, Maastricht, the Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Griez