Effects of suggestion on total respiratory resistance in mild asthmatics

Thirteen mild asthmatics were given inhalations of saline (described as either a neutral substance or a bronchoconstrictor) and Isuprel (described as either a bronchodilator or a bronchoconstrictor). Measurements of Total Respiratory Resistance (R_T) were taken before and after each inhalation. Following inhalations of saline described as a bronchoconstrictor, four subjects evidenced increases in R_T of 20 per cent or more (beyond their responses to saline described as a neutral substance). Some evidence was found of attenuation of the bronchodilative effect of Isuprel when it was described as a bronchoconstrictor. These data corroborate the findings obtained in other investigations, that one subgroup of the asthmatic population responds mainly to the pharmacological effect of the inhalant, while the other subgroup responds to its suggested effect. The observed bronchial changes could not be attributed to the stimulus value of the measurement technique.