Dr MacKenzie explained that the cells containing these genes are present in the amygdala, located deep within the human brain, the primary role of which is in the processing and recall of emotional reactions.
He added that the breakthrough was in focusing on the switches that drive the genes rather than the genes themselves.
He compared it to "moving from looking at a car to examining its engine" and said the distances between the switch and the part of the brain they affected were "as surprising as having a light bulb in London with the switch for controlling it in Liverpool".
Researchers will now join forces with Liverpool University and King's College London to launch a 1 million pound research programme in the hope of finding a cure for the debilitating condition.
They will work with people who have depression to inspect their DNA and look for common changes in their genetic switches.
This could eventually lead to drug treatments, which will target the cause of depression and not just its symptoms.
Source-ANI
RAS/L