It is tied to mood, the reason it&#x27;s more complicated though is that there are many clusters of neuron in the brain which use serotonin to communicate. There are 14 known serotonin receptor subtypes (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;5-HT_receptor#Subtypes" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;5-HT_receptor#Subtypes</a>). Psychedelic drugs (mushrooms, LSD, etc) typically act on 5-HT2a receptors. Serotonin is involved in perceptual filtering, hence why fractal patterns and hallucinations can occur when 5-HT2a is triggered.<p>I would actually say that there&#x27;s a more obvious link between dopamine and mood than serotonin. Dopamine releasers (amphetamines, meth, ritalin, cocaine) produce an immediate uplifting and confidence-boosting effect. MDMA doesn&#x27;t just release serotonin, it also releases dopamine. The serotonin release from MDMA is responsible for its powerful anti-anxiety effect. It&#x27;s believed that the &quot;loved up&quot; feeling from that drug is due to an indirect action of serotonin which eventually produce oxytocin release.