Serotonin is a neurotransmitter, a chemical messenger. Serotonin is responsible for the feeling of happiness. If serotonin is missing, anxiety and depression strike. In severe cases, suicidal thoughts plague those affected.
Alcohol also manipulates the serotonin system. It gives it a kick start. It stimulates the body to release more serotonin. At the same time, it makes the serotonin docking sites in the brain particularly sensitive and ready to receive. So it provides a real serotonin firework twice over. No wonder that alcohol makes you “happy”. At least as long as it is effective.
Once its effect wears off, the good mood is blown away – at least until the next glass.
More in the book “Bye bye, booze!“