Reactivity to a 35% CO2 challenge in healthy first-degree relatives of patients with panic disorder

Biol Psychiatry. 2000 May 1;47(9):830-5. doi: 10.1016/s0006-3223(99)00265-6.


Background: The effects of a 35% CO2 challenge were examined in healthy first-degree relatives of panic disorder patients and in healthy control subjects matched for age and gender.

Methods: One single inhalation of a 35% CO2/65% O2 challenge was administered to 50 first-degree relatives of panic disorder patients and 50 control subjects.

Results: The first-degree relatives were more reactive to the 35% CO2 challenge than the control subjects.

Conclusions: These findings indicate that being a member of a family with a panic disorder patient is, in itself an important factor in CO2 hypersensitivity among subjects who have never experienced a panic attack. Both panic disorder patients and their first-degree relatives have a tendency to be more reactive to the CO2 challenge.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adolescent
  • Adult
  • Carbon Dioxide / pharmacology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Panic Disorder / genetics*
  • Panic Disorder / psychology*
  • Psychiatric Status Rating Scales


  • Carbon Dioxide