What does serotonin do in the brain?

As a neurotransmitter, serotonin helps to relay messages from one area of the brain to another. read more

Mood: Serotonin in the brain is thought to regulate anxiety, happiness, and mood. Low levels of the chemical have been associated with depression, and increased serotonin levels brought on by medication are thought to decrease arousal. read more

Researchers do not know whether serotonin levels in the bloodstream reflect the serotonin levels in the brain, or if SSRIs can really affect the brain. In 2014, a mouse study suggested that serotonin may not play a role in depression. read more