Positive Health Online

Abstract

PIKE and colleagues, Department of Psychiatry, Veterans Affairs Medical Center, San Diego, CA 92161 USA write that life stress is hypothesised to change the dynamic regulation of the autonomic, neuroendocrine and immune systems. The authors studied the effects of chronic life stress upon psychological and physiological responses following challenge with an acute psychological stressor.

Background

Methodology

Male volunteers, 12 with and 11 without chronic life stress were administered a 12-minute laboratory stressor of mental arithmetic vs a video control.

Results

Compared to the video control condition, the effects of the acute psychological stress were: subjective distress, increased concentration of circulating epinephrine, norepinephrine, beta-endorphin, adrenocorticotropic hormone (ACTH) and cortisol, and the selective redistribution of natural killer (NK) cells into peripheral blood. At baseline the two groups were virtually identical regarding psychological, sympathetic, neuroendocrine and immune parameters however, compared to the non stress group, the chronic stress group showed greater subjective distress, higher peak levels of epinephrine, lower peak levels of beta-endorphin and NK cell lysis and greater redistribution of NK cells in response to the acute psychological challenge. Additionally, the acute stressor caused a protracted decline in NK lysis per NK cell in the chronic stress group, but had no effect in the controls.

Conclusion

An exaggerated psychological and peak reactivity occurs when people undergoing chronic life stress are confronted with an acute psychological challenge. This reaction is associated with decrements in individual NK cell function and is protracted beyond termination of the stressor and recovery.

References

Pike JL et al. Chronic life stress alters sympathetic, neuroendocrine, and immune responsivity to an acute psychological stressor in humans. Psychosom Med 59(4): 447-57. Jul-Aug 1997.