This 2013 Zurich study provided details of depression symptoms, particularly in limbic system structures.

As often happens when researchers are absorbed in studying symptoms, there was nothing about treating the causes, in this case, of depression.

Sleep deprivation as a viable therapy for enduring depression? Is that or drugs really all that science has to offer for depression?

http://www.pnas.org/content/110/48/19597.full “Sleep deprivation increases dorsal nexus connectivity to the dorsolateral prefrontal cortex in humans”