RESUMEN
BACKGROUND: Stress is an important factor in the development and maintenance of anxiety disorders. Stress also potentiates anxiety-like response in animals, but empirical evidence for a similar effect in humans is still lacking. METHODS: To test whether stress increases anxiety in humans, we examined the ability of a social stressor (speech and a counting task) to potentiate the facilitation of startle in the dark. Measures of subjective distress and of hypothalamic-pituitary-adrenal axis and autonomic nervous system activity (e.g., salivary cortisol, alpha-amylase, blood pressure, and heart rate) were also taken to confirm the effectiveness of the stress manipulation. RESULTS: Startle was significantly facilitated in the dark. This effect was potentiated by prior exposure to the social stressor. The social stressor induced increases in salivary cortisol and alpha amylase as well as increases in blood pressure, heart rate, and subjective distress. CONCLUSION: The findings indicate that stress potentiates anxiety. Animal studies suggest that such an effect might be mediated by glucocorticoid effects on corticotropin-releasing hormone in limbic structures.