The researchers used brain imaging to explore other brain regions affected by sgACC over-activity during threat. Over-activation of sgACC increased activity within the amygdala and hypothalamus, two key parts of the brain's stress network. By contrast, it reduced activity in parts of the lateral prefrontal cortex - a region important in regulating emotional responses and shown to be underactive in depression.
"The brain regions we identified as being affected during threat processing differed from those affected during reward processing," said Professor Angela Roberts in the University of Cambridge's Department of Physiology, Development and Neuroscience, who led the study.
"This is key, because the distinct brain networks might explain the differential sensitivity of threat-related and reward-related symptoms to treatment."