Bronchoconstrictive suggestion in asthma: a role for airways hyperreactivity and emotions

Using whole-body plethysmographic measurements, asthmatic patients inhaled aerosolized saline presented either as a neutral substance (day 1) or in the guise of a bronchoconstrictor (day 2). Bronchoconstrictive suggestion resulted in increased airway resistance and decreased specific airway conductance, whereas thoracic gas volume was unchanged. The variation in the response was analyzed in relation to airways hyperreactivity, as indexed by methacholine and histamine inhalation challenges, and physiologic measures of the emotional reaction to bronchoconstrictive suggestion, as indexed by changes in blood pressure, heart rate, finger pulse amplitude, and forehead electromyographic activity. It was found that the bronchoconstrictive response was significantly related to the degree of airways hyperreactivity and to the emotional response. These results suggest that asthmatic patients apt to respond to bronchoconstrictive suggestion with airways obstructions are characterized by highly hyperreactive airways. Responders also appear to be emotionally labile, although it is not yet clear whether the emotional response per se evokes airway obstruction or is merely a by-product of the occurrence of airway obstruction.