Chronic Stress Shrinks the Brain
Yale team discovers how chronic stress and depressions can shrink the brain.
Chronic stress is defined as extreme or moderate stress, continuing for more than six months. In K-12 schools it may continue for five or more years.
Major depression or chronic stress can cause the loss of brain volume, a condition that contributes to both emotional and cognitive impairment. Now a team of researchers led by Yale scientists has discovered one reason why this occurs — a single genetic switch that triggers loss of brain connections in humans and causes depression in animal models. The findings show that the genetic switch known as a transcription factor represses the expression of several genes that are necessary for the formation of synaptic connections between brain cells, which in turn could contribute to loss of brain mass in the prefrontal cortex. “We wanted to test the idea that stress causes a loss of brain synapses in humans,” said senior author Ronald Duman, the Elizabeth Mears and House Jameson Professor of Psychiatry and professor of neurobiology and of pharmacology. “We show that circuits normally involved in emotion, as well as cognition, are disrupted when this single transcription factor is activated.” SOURCE: http://news.yale.edu/2012/08/12/yale-team-discovers-how-stress-and-depression-can-shrink-brain
Brain shrinking reduces large number of brain capacities in the pre-frontal cortex and Amygdala.