Men, women respond differently to stress

PHILADELPHIA, Nov. 21 (UPI) -- Men have a "fight-or-flight" response to stress while women are more likely to "tend-and-befriend," a U.S. researcher suggests.

University of Pennsylvania School of Medicine researchers found that different parts of the brain activate with different spatial and temporal profiles for men and women when they are faced with performance-related stress.

Lead author J.J. Wang said evolutionarily, males may have had to confront a stressor either by overcoming or fleeing it, while women may have responded by nurturing offspring and affiliating with social groups that maximize the survival of the species.

Thirty-two healthy subjects -- half of them women -- received functional magnetic resonance imaging scans before, during and after they underwent a challenging arithmetic task, under pressure. As a low stress control condition, participants were asked to count backward without pressure.

The researchers measured regional cerebral blood flow -- a marker of regional brain function.

In men, stress was associated with increased cerebral blood flow in the right prefrontal cortex and cerebral blood flow reduction in the left orbitofrontal cortex -- associated with higher levels of the stress hormone cortisol. The limbic system -- a part of the brain primarily involved in emotion -- was activated when the women were under stress, reported the journal Social Cognitive and Affective Neuroscience.