The Montreal Type A Intervention Project: major findings.

This article reports a comparison of three short-term treatments (aerobic exercise, cognitive-behavioral stress management, and weight training) in modifying behavioral and cardiovascular reactivity to laboratory psychosocial stressors in healthy Type A men. One hundred seven men completed the treatments and evaluations, 33 in the aerobic exercise group, and 37 each in the cognitive-behavioral stress management and weight-training groups. The stress management group showed significantly greater changes in behavioral reactivity (reductions of 13% to 23% below initial values) than the two physical exercise groups, which did not differ significantly from each other. For physiological reactivity, changes attributable to intervention were trivial for all three treatment groups. The positive finding of reduced behavioral reactivity as a result of the stress management intervention is of potential clinical significance and warrants further exploration. The lack of meaningful reductions in physiological reactivity also requires further exploration in that it raises questions concerning the ability of behavioral treatments in general to modify physiological reactivity, the ability of existing measures to assess accurately changes that are produced and, most fundamental of all, the relevance of physiological reactivity as an outcome measure for treatment efforts with Type As.

Exaggerated psychophysiological reactivity: issues in quantification and reliability.

Marked physiological reactivity to challenging mental tasks has been associated with elevated risk for, as well as the presence of, coronary heart disease. However, little systematic enquiry into the reliability and quantification of such exaggerated reactivity has emerged. Subjects were 32 male, managerial employees, ranging in age from 22 to 56 yr, who satisfied the following criteria: no history or current signs of heart disease, presence of Type A behavior pattern as revealed by the Structured Interview, and an increase during an initial psychosocial stress testing of at least 25% over baseline in at least three out of five psychophysiological indices. Heart rate, systolic blood pressure, diastolic blood pressure, plasma epinephrine and plasma norepinephrine levels were monitored while challenging mental tasks were performed in three sessions (screening, pretraining and posttraining) spaced several weeks apart. Psychophysiological reactivity during the tasks emerged as a consistent trait. For all five measures, change scores from baseline during the screening session were significantly correlated with change scores during the pretraining session. Moreover, the magnitude of the change scores were similar in the screening and pretraining sessions. Analysis of cross correlations within and between indices provided little support for the use of data transformations such as residual scores or analysis of covariance. Finally, on four out of five measures, the challenging tasks were found to be comparable in the degree of reactivity elicited. These findings suggest that, for selected Type A men, exaggerated psychophysiological reactivity occurs reliably when monitored with multiple indices, appears insensitive to mere passage of time, and can be uniformly elicited by a variety of tasks.