CARBON-DIOXIDE HYPERSENSITIVITY, HYPERVENTILATION, AND PANIC DISORDER

Objective of this article is to offer a comprehensive, data-based expl anation of the relationship between hyperventilation and panic disorde r linking CO2 hypersensitivity, cognitive/behavioral factors, and the respiratory effects of antipanic pharmacologic and psychological treat ments. Methods: The authors conducted a computerized search of MEDLINE for relevant articles. Results: Some panic patients have a chronic, s ubtle respiratory disturbance. Acute hyperventilation is neither neces sary nor sufficient for panic to occur. Respiratory abnormalities in p anic patients may adaptively aim at coping with a hypersensitive CO2 c hemoreceptor system. Pharmacologic panicogens also stimulate the respi ratory system, causing hyperventilation. Triggering this hypersensitiv e respiratory control mechanism may in panic. Antipanic medications ma y reset the receptor threshold. Misattribution and catastrophic interp retation of somatic symptoms or the sense of loss of control may contr ibute to panic symptoms. Behavioral interventions such as desensitizat ion or breathing retraining may block the full-blown attack. Cognitive strategies through cognitive control of respiration may supplement an d accentuate these interventions. Conclusions: Panic disorder may be d ue to an inherently unstable autonomic nervous system, coupled with co gnitive distress.