Neurosciencecalendar_todayLast updated: Apr 2026
What is Serotonin?
/ˌsɛrəˈtəʊnɪn/
Serotonin is a neurotransmitter that regulates mood, sleep, appetite, and social behaviour. Low serotonin levels are associated with depression, anxiety, and impulsive behaviour.
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Everyday Example
The calm, contented feeling after a satisfying meal, a good night's sleep, or a kind interaction with a friend is partly mediated by serotonin.
publicReal-World Application
“SSRIs (Selective Serotonin Reuptake Inhibitors) like Prozac and Sertraline, used to treat depression in over 40 million people globally, work by increasing serotonin availability in the brain.”
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Did you know?
Serotonin was discovered in the 1940s, first in blood (hence the name — "serum tone"). Its role in the brain was only understood in the 1950s.
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Key Insight
95% of your body's serotonin is actually produced in the gut, not the brain — reinforcing the emerging science of the gut-brain connection and why diet affects mood so profoundly.
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