Control and intrusive memories as possible determinants of chronic stress.

Amidst confusion about the nature and usefulness of the stress construct and distinctions between acute and chronic stress, research has begun to identify mechanisms by which stress affects health and by which stress can persist beyond the physical presence of the stressor. In addition, research has begun to identify reasons for selective vulnerability to chronic stress. One of the possible reasons for chronic stress following traumatic events is the disorganizing effect of loss of control and violation of expectations for regulating aspects of one's life normally under control. Data from a longitudinal study of chronic stress at Three Mile Island in the wake of the nuclear accident there suggest that loss of control and frequent experience of intrusive memories about the accident and its aftermath were related to persistent stress responding several years after the accident. The relationships between stress responding and conditioning and consolidation of stressful memories are considered as a basis for persistent intrusive memories and chronic stress.