Differential carbon dioxide sensitivity in childhood anxiety disorders and nonill comparison group.
BACKGROUND
To examine the relationship between respiratory regulation and childhood anxiety disorders, this study considered the relationship between anxiety disorders and symptoms during carbon dioxide (CO(2)) exposure, CO(2) sensitivity in specific childhood anxiety disorders, and the relationship between symptomatic and physiological responses to CO(2).


METHODS
Following procedures established in adults, 104 children (aged 9-17 years), including 25 from a previous study, underwent 5% CO(2) inhalation. The sample included 57 probands with an anxiety disorder (social phobia, generalized anxiety disorder, separation anxiety disorder, and panic disorder) and 47 nonill comparison subjects. Symptoms of anxiety were assessed before, during, and after CO(2) inhalation.


RESULTS
All children tolerated the procedure well, experiencing transient or no increases in anxiety symptoms. Children with an anxiety disorder, particularly separation anxiety disorder, exhibited greater changes in somatic symptoms during inhalation of CO(2)-enriched air, relative to the comparison group. During CO(2) inhalation, symptom ratings were positively correlated with respiratory rate increases, as well as with levels of tidal volume, minute ventilation, end-tidal CO(2), and irregularity in respiratory rate during room-air breathing.


CONCLUSIONS
Childhood anxiety disorders, particularly separation anxiety disorder, are associated with CO(2) hypersensitivity, as defined by symptom reports. Carbon dioxide hypersensitivity is associated with physiological changes similar to those found in panic disorder. These and other data suggest that certain childhood anxiety disorders may share pathophysiological features with adult panic disorder.
Pine
D S
DS
New York State Psychiatric Institute, Box 74, 1051 Riverside Dr, New York, NY 10032, USA. Pined@child.cpmc.columbia.edu
Klein
R G
RG
Coplan
J D
JD
Papp
L A
LA
Hoven
C W
CW
Martinez
J
J
Kovalenko
P
P
Mandell
D J
DJ
Moreau
D
D
Klein
D F
DF
Gorman
J M
JM
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001008:Anxiety Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D001010:Anxiety, Separation / Q000175:diagnosis / Q000503:physiopathology; D002245:Carbon Dioxide / Q000494:pharmacology; D002648:Child; D006801:Humans; D016584:Panic Disorder / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D010555:Personality Inventory / Q000706:statistics & numerical data; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012119:Respiration / Q000187:drug effects; D012143:Respiratory Physiological Phenomena / Q000187:drug effects*; D013990:Tidal Volume / Q000187:drug effects
D002245:Carbon Dioxide