These notes are taken from RSD Websites and medical articles which shed light on why RSD can lead to depression and information on treatment. Grateful acknowledgement is given to all sources. The extracts have been arranged in an order that presents a theoretical explanation for RSD induced depression. The author has seen the effects first hand within his own family.

Serotonin
In the central nervous system, serotonin is believed to play an important role in the regulation of anger, aggression, body temperature, mood, sleep, vomiting, sexuality, and appetite. Low levels of serotonin have been associated with several disorders, namely increase in aggressive and angry behaviors, clinical depression, Obsessive-compulsive disorder (OCD), migraine, irritable bowel syndrome, tinnitus, fibromyalgia, bipolar disorder and intense religious experiences.                                             From Wikipedia

Most cerebral functions are the result of the convergence of many different neurotransmitters, including serotonin. This complex network of neurotransmitters makes it possible for serotonin to affect many functions and actions of the brain. For example, serotonin often serves as a co-transmitter along with gamma-amino butyric acid (GABA) and norepinephrine. Serotonin antagonizes GABA_B receptors, causing up-regulation of this subtype.                                                               From ‘US Pharmacist’

Serotonin Receptors

Serotonin occurs naturally in the body. In the periphery, serotonin acts both as a gastrointestinal regulating agent and a modulator of blood vessel tone. Although only 2% of the body’s serotonin is found in the brain as a neurotransmitter, the chemical can have a profound effect on body functions. As a neurotransmitter, serotonin is involved in the modulation of motor function, pain perception, appetite, and outflow from the sympathetic nervous system.                                                         From ‘US Pharmacist’

Serotonin acts at receptors generally classified into one of four categories, depending upon function and location. The four recognized serotonin receptors identified are 5-HT₁, 5-HT₂, 5-HT₃ and 5-HT₄. Receptor subtypes also have been identified. For example, the 5-HT_1d subtype lies outside the CNS and is the receptor through which sumatriptan exerts its anti-migraine effect. The 5-HT₂ receptors are located in the brain and peripheral blood vessels.                   From Molecular Biology of Serotonin Receptors by Jean Chen Shih, Kevin J.-S. Chen and Timothy K. Gallaher

Selective serotonin reuptake inhibitors (SSRIs) – Medications used to relieve depression by increasing the availability of serotonin in the brain. By increasing this chemical’s availability, these drugs modify neuronal pathways involved in regulating mood

                                                                From MayoClinic.com 2005, Medline Plus 2006

Summary

RSD pain impacts upon serotonin, moving it out of the brain to the limbs, and disrupts its function in the mid-brain and hypothalamus causing depression and non rational thought.

© Tim Anderson 2007