How stress can tweak the brain to sabotage self-control

http://www.eurekalert.org/pub_releases/2015-08/cp-hsc072915.php

Public Release: 5-Aug-2015
How stress can tweak the brain to sabotage self-control
Cell Press

A challenging morning meeting or an interaction with an upset client at work may affect whether we go for that extra chocolate bar at lunch. In a study appearing August 5 in Neuron, researchers placed human volunteers in a similar food choice scenario to explore how stress can alter the brain to impair self-control when we're confronted with a choice.

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he scientists found that when individuals chose between different food options after having experienced the stressful ice bath treatment, they overweighed food taste attributes and were more likely to choose an unhealthy food compared with people who were not stressed.

The effects of stress were also visible in the brain. Stressed participants' brains exhibited altered patterns of connectivity between regions including the amygdala, striatum, and the dorsolateral and ventromedial prefrontal cortex, essentially reducing individuals' ability to exercise self-control over food choices. Only some of these changes were associated with cortisol, a hormone commonly linked to stress.

The investigators say that their study indicates that even moderate levels of stress can impair self-control. "This is important because moderate stressors are more common than extreme events and will thus influence self-control choices more frequently and for a larger portion of the population," says senior author Todd Hare. "One interesting avenue for future research will be to determine whether some of the factors shown to protect against structural brain changes following severe stress--such as exercise and social support--can also buffer the effects of moderate stress on decision making," he adds.

There was also a good deal of variation in the degree to which stress affected individuals in the study, so it will be important to investigate why some people are more resilient than others.