<qa>  What is the cause of the pathological version of sadness that people with Major Depression experience?There is good evidence to suggest that the pathological version of sadness that people with Major Depression experience could be caused by the failure of the hormone cortisol to properly inhibit sadness-related brain activity in the subgenual cingulate cortex. This project investigates if the subgenual cingulate cortex has become insensitive to cortisol in patients with depression and tests for variants of the cortisol receptor genes that could predispose individuals to develop cortisol insensitivity. 