Mounting evidence continues to show that ketamine helps with fibromyalgia. There is still much to be understood about how ketamine alleviates fibromyalgia. Scientists tend to focus on ketamine’s ability to boost the activity of glutamate, a neurotransmitter found throughout the central nervous system. This heightened glutamate activity allows new pathways to form in areas of the brain associated with memory, learning, and mood regulation. Importantly, heightened glutamate corresponds with the inhibition of NMDA receptors which are associated with the physical experience of pain. Researchers are starting to see that the positive effects of many antidepressants may be a result of regulating glutamate, although less directly than ketamine. Because of this indirect process, SSRIs and tricyclic antidepressants often take weeks to start improving symptoms of fibromyalgia, if they do at all. Ketamine often produces results and relief from fibromyalgia symptoms during the first session.