A neurotransmitter (a type of chemical that nerve cells use to communicate with one other) that appears to be involved in mood, appetite, sleep, intestinal motility, memory, and learning. Disruption in serotonin levels may play a role in fibromyalgia, a syndrome characterized by pain, stiffness, multiple tender points throughout the body, and fatigue.
Medicines that raise the body’s serotonin levels are used in the treatment of depression and generalized anxiety disorder. Monoamine oxidase inhibitors (MAOIs) prevent the breakdown of serotonin in the brain, thus increasing its levels. Tricyclic antidepressants inhibit the reuptake of serotonin and another neurotransmitter called norephinephrine, increasing the levels of those substances in the brain. Selective serotonin reuptake inhibitors (SSRIs) also inhibit the reuptake of serotonin, but with fewer side effects and interactions with other drugs. Since fibromyalgia appears to be associated with disruption in serotonin levels, certain drugs that increase serotonin levels, such as duloxetine (Cymbalta) and milnacipran (Savella), are sometimes used to treat fibromyalgia.