Most depression doesn’t start in the brain.
14 Jul 2025 · 1 min

0:41
Short German dialogue from a YouTube video arguing that most depression doesn’t originate in the brain but in the body (primarily the gut). The speakers describe serotonin synthesis from the amino acid tryptophan, note that ~90% of serotonin is located outside the brain, describe a methylation step and vagus-nerve signaling to the brain, and claim that inability to produce peripheral serotonin prevents certain mood states and leads to psychiatric diagnoses followed by synthetic pharmaceuticals.










