Airway resistance and emotional state in bronchial asthma.

Whole-body plethysmograph measurements and challenge inhalation of carbachol were combined to assess asthmatic changes longitudinally. Airway conductance proved to be relatively stable over a 10-week period in 3 normal subjects. Five asthmatics showed periodically lower conductance and greater variability. Periods of low conductance at times could be observed to precede other manifestations of oncoming major attacks. Change in conductance upon challenge with a bronchoconstrictor drug appeared to fluctuate, even when correction was made for the initial level. It appeared to be a further index of variation in subliminal vulnerability of the individual. Blind ratings of a variable assessing "defensive strain" correlated with increases in sensitivity to carbachol in 2 subjects. Our hypothesis was that defensive breakdown may lead to a lack of homeostatic regulatory control, which in turn may play a part in the waxing and waning of the asthmatic process; it received support from these preliminary observations.