Reduction in type A behavior in healthy middle-aged American military officers.

One hundred eighteen senior officer-students of the U.S. Army War College who were healthy but exhibited type A behavior volunteered to be randomly selected and enrolled into (1) a section of 62 officers who received group type A behavior counseling for 9 months and (2) a control section of 56 officers who received no counseling of any kind. Marked or profound reduction in type A behavior at the end of 9 months was observed in 41.9% of the 62 participants who initially were enrolled to receive type A counseling; marked or profound reduction in type A behavior, however, was observed in only 8.9% of the 56 initially enrolled control subjects. No adverse effects on the military leadership qualities of type A counseled participants were observed by their classmates. Serum total cholesterol and plasma high-density lipoprotein (HDL) cholesterol measurements were obtained monthly. The serum cholesterol of the total cohort of subjects rose significantly during a month of considerable emotional tension and stress. Those subjects who underwent a profound reduction in the intensity of their type A behavior pattern also exhibited a significantly lower serum cholesterol value as the study continued than those subjects who exhibited no change in their type A behavior. No significant changes in plasma HDL cholesterol concentrations were observed in the total cohort during the above-mentioned period of stress, nor were any differences in this particular measurement noted between the type A counseled and the control participants.