Central and peripheral chemoreflex characteristics: panic disorder patients vs. healthy volunteers.

Panic disorder is a psychiatric condition characterised by spontaneous panic attacks. These are discrete episodes of intense anxiety that are perceived to be uncontrollable and are accompanied by unpleasant physical sensations such as palpitations, chest pain, dyspnea, choking, sweating, tremors, faintness and paraesthesia. Although successful treatments for the condition are available, its etiology remains elusive1. In 1993 Klein has suggested that panic disorder patients possess a “false suffocation alarm” that may be associated with a lowered threshold for carbon dioxide detection2. The theory attributes carbon dioxide hypersensitivity as a causal instigator for panic in these patients, with carbon dioxide as the physiological messenger for detecting potential suffocation. To date there has been no assessment of the respiratory suffocation sensors, namely the central and peripheral chemoreflexes, in response to rising carbon dioxide levels.