The areas of the brain that are affected by depression have been identified, and this could open up new possible treatments, researchers have said.
The study, by the University of Warwick and Fudan University, China, shows that depression affects the part of the brain that is implicated in non-reward - the lateral orbitofrontal cortex – so that people with the condition feel a sense of loss and disappointment associated with not receiving rewards.
This area of the brain, which becomes active when rewards are not received, is also connected with the part of the brain that is involved in one’s sense of self, thus potentially leading to thoughts of personal loss and low self-esteem.
Depression is also associated with reduced connectivity between the reward brain area in the medial orbitofrontal cortex and memory systems in the brain, which could account for people with the condition having a reduced focus on happy memories.
These new discoveries could herald a breakthrough in treating depression, by going to the root cause of the illness and helping depressed people to stop focusing on negative thoughts.
The study was carried out by Professor Edmund Rolls from Warwick, Professor Jianfeng Feng from Warwick and from Fudan University in Shanghai, Dr Wei Cheng from Fudan University, and by other centres in China.
In the study, almost 1,000 people in China had their brains scanned using high precision MRI, which analysed the connections between the medial and lateral orbitofrontal cortex - the parts of the human brain affected by depression.
“More than 1 in 10 people in their lifetime suffer from depression, a disease which is so common in modern society and we can even find the remains of Prozac (a depression drug) in the tap water in London,” said Professor Feng.
“Our finding, with the combination of big data we collected around the world and our novel methods, enables us to locate the roots of depression which should open up new avenues for better therapeutic treatments in the near future for this horrible disease.”
Professor Rolls looks added that the research could lead to new treatments: “The new findings on how depression is related to different functional connectivities of the orbitofrontal cortex have implications for treatments in the light of a recent non-reward attractor theory of depression. [doi: 10.1016/j.neubiorev.2016.05.007].”
The research, ‘Medial reward and lateral non-reward orbitofrontal cortex circuits change in opposite directions in depression’, is published in Brain.