Controllable and uncontrollable stress in humans: alterations in mood and neuroendocrine and psychophysiological function.

The authors exposed 10 healthy human volunteers to the stress of loud (100 dB) noise under controllable and uncontrollable conditions on two separate days. Subjects reported higher self-ratings of helplessness, lack of control, tension, stress, unhappiness, anxiety, and depression; had greater hypothalamic-pituitary-adrenal axis function as measured by elevations in plasma adrenocorticotropic hormone; and had higher levels of sympathetic nervous system and electrodermal activity after the uncontrollable stress condition than after exposure to controllable stress. Thus, lack of control over even a mildly aversive stimulus can produce alterations in mood as well as neuroendocrine and autonomic nervous system changes in healthy subjects.