It's not so much that neurotransmitter levels are just lower than they should be - reuptake inhibitors fix that problem very quickly.... A more nuanced modern

It's not so much that neurotransmitter levels are just lower than they should be - reuptake inhibitors fix that problem very quickly.... A more nuanced modern understanding that we have now is that the increased levels of neurotransmitters in the brain signal the neurons to form more synapses, and this increase in grey matter in key brain regions, over months, is what has been repeatedly shown to improve the condition. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790407/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790407/ https://www.ncbi.nlm.nih.gov/pubmed/23988273 https://www.ncbi.nlm.nih.gov/pubmed/23988273 Specifically, serotonin-induced synaptic plasticity changes in the anterior cingulate and orbital prefrontal cortex allow the old brain (limbic emotional areas) and new brain (neocortex) to communicate better.