Comment · Thu, January 9, 2014 · Ceretropic
Effects of antidepressant drugs on synaptic protein levels and dendritic outgrowth in hippocampal neuronal cultures
What they were answering
xsiv1 · 2 points
There are those who are also purporting that this is also likely the true reason as to why some SSRI's work. Many chronically depressed patients have displayed atrophy in this very region of the brain. The question was raised I think, when they found that even drugs that do the opposite of SSRI's also worked which questioned the mechanism of action.
u/MisterYouAreSoDumb · Ceretropic
Because they work on different sub-systems and pathways that lead to the BDNF increase. This study showed that tianeptine relied on phosphatidylinositide 3-kinase enzymes to increase BDNF levels, while the others did not.
Also, take a look at this study. That found that MDMA decreased BDNF in the hippocampus, but increased it in the frontal cortex. So compounds that work on totally different systems can have similar effects in different brain regions.