In a new study, scientists have demonstrated that disrupted production of new neurons in mice can lead to severe depression following intense stress, and have identified a hormone that protects newly developed neurons.
The production of new neurons in the hippocampus of both mice and humans is known as neurogenesis, and is a process that continues to happen throughout adulthood. The hippocampus is the part of the brain that affects mood, memory, and hunger. When this neurogenisis is disrupted in mice, they were more likely to suffer the symptoms of depression.
There is a hormone in the body called ghrelin, and it is produced mainly in the stomach and works to suppress appetite after eating. It also has the affect of protecting new neurones when they are created, which means that the more ghrelin there is, the more protected against depression a person will be.
New neurones can be damaged by several neurological issues, including depression itself, and so if people have low levels of ghrelin, this study suggests they will be more susceptible to deeper and more chronic depression.
The link between ghrelin and depression could open up new avenues for research into treating and preventing depression.