SSRIs appear to work through the vagus nerve in a similar way to psychobiotics. Their direct effects on neurotransmitters are probably an unwanted side-effect:
To add to my comment, this explains why SSRIs take some time to work - it's the signalling through the vagus nerve that takes time to impact the brain. Other compounds such as curcumin and famotidine (H2 antihsitamine) have also been found to work via this mechanism. For many many years scientists had dismissed curcumin as having no effect because it's not bioavailable - recent research has shown that it doesn't need to be if it directly activates your nervous system! There's a lot more research that needs to be done here, and I think promising therapeutics for impacting brain function are coming our way as researchers learn more.
If you consider the brain a state machine, inputs from the nerves - through gut-brain axis, through your eyes and ears (socialising, environmental cues, sounds of safety vs sounds of threat), through your skin (touch) etc all impact the state. This state can range from safety to fight-or-flight (anxiety) to shutdown (depression). This is hugely simplified (for example neuroinflammation, endotoxins/LPS etc can impact this also) but I've found it very useful for regulating my own state and understanding why I feel happy, agitated, low etc.
recently procured an acupressure spiky foot ball that was originally designed to combat depression by stimulating the vagus through the foot. I don't consider myself depressed by any means, but after a few minutes of rolling my feet aggressively over the ball and targeting a few key areas, I generally feel much better and can actually sense that my body is less stressed. everyone should have one or 2 of them
This is very interesting - is that just a general acupressure spikey ball? I am looking for one on Amazon, if you had the link?
Also, reading up on the vagus how is the vagus stimulated via the foot? Reading on wikipedia on the vagus nerve I cannot see how it is connected to the foot in any way?
If you consider the brain a state machine, inputs from the nerves - through gut-brain axis, through your eyes and ears (socialising, environmental cues, sounds of safety vs sounds of threat), through your skin (touch) etc all impact the state. This state can range from safety to fight-or-flight (anxiety) to shutdown (depression). This is hugely simplified (for example neuroinflammation, endotoxins/LPS etc can impact this also) but I've found it very useful for regulating my own state and understanding why I feel happy, agitated, low etc.