Consistent with a wealth of animal research documenting the effects of stress on amygdala structure and function (3), emerging human research has linked acute stress during adulthood, severeforms of childhoodemotional neglect (e.g., institutional rearing), and hypercortisolemia with heightened amygdala reactivity and greater volume (4–10). Circumstantial behavioral and physiological evidence is consistent with these novel neural findings: individuals who were abused or neglected during childhood have an attentional bias toward threatening stimuli (11), childhood abuse is associated with a potentiated fear startle response (12), and stress has been shown to facilitate memory for emotional content but to disrupt memory for neutral content (13). In other studies (14–16), these stress-sensitive startle, attentional, and mnemonic biases were linked with elevated amygdala reactivity. Because the amygdala undergoes rapid development during childhood, researchers have postulated that childhood through early adolescence may be a critical period during which the amygdala is particularly sensitive to stress (3). Collectively, these results suggest that stress exposure, particularly during childhood, promotes heightened amygdala reactivity, which may precipitate the development of psychopathology.
