How Depression Affects The Brain - Yale Medicine Explains

For decades, we thought that the primary pathology, the primary cause of depression was some abnormality in these neuro-transmitters, specifically serotonin or norepinephrine.

However, norepinephrine and serotonin did not seem to be able to account for the symptoms of depression in people who had major depression.

Instead, the chemical messengers between the nerve cells in the higher centers of the brain involved in regulating mood and emotion, which include glutamate and GABA, were possibilities as alternative causes for the symptoms of depression.

When you treat that depression effectively, the brain goes back to looking like a healthy brain.