Early life stress and adolescent depression cause impaired development of reward circuits

http://www.eurekalert.org/pub_releases/2015-10/e-els102915.php

Public Release: 29-Oct-2015
Early life stress and adolescent depression cause impaired development of reward circuits
Reports new study in Biological Psychiatry
Elsevier

Early life stress is a major risk factor for later episodes of depression. In fact, adults who are abused or neglected as children are almost twice as likely to experience depression.

Scientific research into this link has revealed that the increased risk following such childhood adversity is associated with sensitization of the brain circuits involved with processing threat and driving the stress response. More recently, research has begun to demonstrate that in parallel to this stress sensitization, there may also be diminished processing of reward in the brain and associated reductions in a person's ability to experience positive emotions.

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"Our analyses revealed that over a two-year window during early to mid-adolescence, there was an abnormal decrease in the response of the ventral striatum to reward only in adolescents who had been exposed to emotional neglect, a relatively common form of childhood adversity where parents are persistently emotionally unresponsive and unavailable to their children," explained first author Dr. Jamie Hanson.

"Importantly, we further showed that this decrease in ventral striatum activity predicted the emergence of depressive symptoms during this key developmental period," he added. "Our work is consistent with other recent studies finding deficient reward processing in depression, and further underscores the importance of considering such developmental pathways in efforts to protect individuals exposed to childhood adversity from later depression."

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