Scientists and doctors long baffled by the multiple causes and brain processes for depression may now have a single "holy grail" brain pathway to focus on for treatment, according to a new research study released Thursday.
Studying the brains of rats, researchers at the Stanford University School of Medicine have discovered a single brain circuit that appears to funnel all the mechanisms and treatments of depression.
Depression-related behavior is manifested in changes in electrical signals moving through the circuit, according to the study released on the journal Science's website.
Karl Deisseroth, a professor of bioengineering and of psychiatry and behavioral sciences, said the circuit can help explain why there can be many causes and treatments of depression.
"It also helps us understand conceptually how something that seems as hard to get traction on as depression can have a really quantitative, concrete basis," he said in a summary of the study.
Deisseroth led a research team to see if they could demonstrate how malfunctions in brain circuitry could be at the root of depression.
They studied the electrical activity of still-active slices of the hippocampus section of rat brains treated with flourescent dye, using high-speed high-resolution cameras to record activity in brain neurons in real time.
According to Deisseroth, rat brains show similar depression symptoms to human ones and react to anti-depression medicines in the same way.
The testing showed that an alteration in electrical activity flow through the brain could be readjusted with the use of human drugs against depression -- suggesting the existence of a specific circuit for the condition.
According to Deisseroth, the discovery of the single circuit for depression could lead to methods doctors could use to better diagnose and quantify the problem in their human patients.
"The holy grail of psychiatry is to try to find final common pathways that can make sense of how genes and life experiences end up with the same result," he said.
"And the same goes for medications. There are many treatments that act in fundamentally different ways -- how do we make sense of all that complexity?"