We all get the blues sometimes, but for the 15.7 million Americans impacted by depression each year, feelings of worthlessness, sadness and hopelessness don’t go away. Depression is one of the most common mental disorders in the United States, and the number of Americans taking antidepressants is on the rise. A 2013 New York Times article estimates that one in 10 adults are now medicated for depression.
With so many people turning to medication for help with chronic depression, it is more important than ever to figure out exactly what is going on in the brain of those afflicted with this debilitating disorder. The pathophysiology of depression is crucial in fighting it. Though we have long pointed to dopamine and serotonin receptors as the key feature of mood disorders, new evidence is emerging to paint a more complete picture.
Recent studies have found atrophy and the loss of hippocampal neurons in patients suffering from depression. In extreme cases, this region of the brain has been documented to shrink by nearly 20 percent. It is no wonder people with chronic depression often suffer from decreasing cognitive abilities. Sadly, this atrophy appears to be permanent.
Researchers at Yale University set out to look at how antidepressants might impact this crucial part of the brain. Using the thymidine analog bromodeoxyuridine (BrdU) to identify dividing cells in the hippocampus, these researchers tested antidepressants on a number of rats. They found that antidepressants did indeed lead to increased cell division. The new cells matured into neurons, and revitalized neuronal activity in the hippocampus. This result applied to several antidepressants agents, but did not materialize when non-antidepressant agents were used.
The study concludes that increased cell proliferation may be a mechanism through which antidepressants effectively treat depression. Hopefully, these findings will eventually be put to use helping people who suffer from depression.