/October 11, 2012 by Damon Lavrinc Instead, the studies reviewed here support a different theory, one which suggests that depression is the result of damage to the brain cells responsible for controlling mood. In mice, at least, this atrophy of neurons occurred in response to stress. Although the reasons stress causes this to happen are unclear, the weakening of synaptic connections appears to be at the root of depression and other stress-related disorders. — Lindsay Abrams for the Atlantic writing about the effects of Ketamine on patients suffering from depression. But forget about Special K. The real news is that we’ve been wrong about the biological causes and treatments of depression.