# Serotonin --- **Serotonin** is an important monoamine [[neurotransmitter]] that is associated with mood, anxiety and happiness. It plays a big role in the social aspect of life. It also affects: - sleep and arousal - libido - appetite - aggression - pain perception - coordination - judgement (i.e. risk-taking). However, the vast majority of the serotonin in the body (over 90%) regulates the movement and function of the [[gastrointestinal tract]]. ## Imbalances with Serotonin - increased levels of serotonin can contribute to: - heightened anxiety - serotonin syndrome (see below) - decreased levels of serotonin can contribute to: - [[depression]] ### Serotonin Syndrome **Serotonin syndrome** is a condition where there is too much [[serotonin]] in the body. It can cause signs and symptoms such as: - agitation/confusion - diarrhea - fever - hallucinations - tachycardia - nausea/vomiting - seizures Be careful with patients taking things like [[SSRIs]] and/or [[selective serotonin agonists]]. ___