Carbon dioxide-induced anxiety. Behavioral, physiologic, and biochemical effects of carbon dioxide in patients with panic disorders and healthy subjects

Arch Gen Psychiatry. 1988 Jan;45(1):43-52. doi: 10.1001/archpsyc.1988.01800250051007.


Carbon dioxide was administered for 15 minutes to patients with panic disorders (5% CO2, n = 14) and healthy subjects (5% CO2, n = 11; 7.5% CO2, n = 8). Following administration of CO2 and air placebo, changes in behavioral ratings, vital signs, and plasma levels of the norepinephrine metabolite 3-methoxy-4-hydroxyphenylglycol, cortisol, growth hormone, and prolactin were measured over three hours. In the healthy subjects, CO2 produced dose-related increases in anxiety, somatic symptoms, vital signs, and plasma cortisol levels. In the patients, the frequency of panic attacks (in eight of 14 patients) and the increases in anxiety and somatic symptoms induced by 5% CO2 exceeded those in the healthy subjects and were similar to those induced by 7.5% CO2 in the healthy subjects. The physiologic and biochemical measurements obtained did not elucidate the mechanisms underlying CO2-induced anxiety or the greater anxiogenic effects of CO2 seen in patients with panic disorders.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Anxiety Disorders / chemically induced*
  • Anxiety Disorders / psychology
  • Carbon Dioxide* / administration & dosage
  • Carbon Dioxide* / pharmacology
  • Emotions / drug effects
  • Fear*
  • Female
  • Growth Hormone / blood
  • Humans
  • Hydrocortisone / blood
  • Male
  • Methoxyhydroxyphenylglycol / blood
  • Middle Aged
  • Panic*
  • Personality Inventory
  • Prolactin / blood


  • Carbon Dioxide
  • Methoxyhydroxyphenylglycol
  • Prolactin
  • Growth Hormone
  • Hydrocortisone