Carbon Dioxide Sensitivity and Personality

Abstract

Although respiratory physiologists have long noted marked interindividual differences in ventilatory response to CO2, these differences have not been related previously to personality. In this study, 33 volunteer test subjects underwent 3 or 4 trials of a rebreathing test for CO2 sensitivity. During each trial the increase in the subject's ventilation was related to increase in alveolar CO2. The subjects were also administered the Minnesota Multiphasic Personality Inventory (MMPI). Elevations were noted on nearly all standard scales of the MMPI for low responders to carbon dioxide, with the differences between high and low responders reaching statistical significance on several scales. Differences in personality traits between high and low responders to CO2 suggests that this test may be useful for psychosomatic investigations. The interpretation of CO2 sensitivity as an index of the excitatory level of the respiratory center in the medulla is discussed.