This is paraphrased and quoted: In This Article Drugs in the Pipeline Substance P Antagonists (SPAs): New Class of Drugs Show Promise in Treating Depression from The Brown University Psychopharmacology Update Posted 04/08/2003 Substance P antagonists (SPAs) represent a new class of promising compounds being investigated to treat depression and associated anxiety. According to a review by Patrick W. Mantyh, Ph.D., in the Journal of Clinical Psychiatry, substance P (SP) belongs to the neurokinin (NK) family of neuropeptides and interacts with the NK1 receptor. It regulates affective behavior and the perception of pain (nociception). SP is released in response to stressful stimuli, with the amount released depending on the frequency and intensity of the stressful stimulation. More intense and more frequent stimulation also diffuses SP further from its site of release. The name of this drug is aprepipant. It is in phase II studies for treatment of depression and anxiety, it worked better than paroxetine (an SSRI), and had fewer side effects. It is also being looked at for treatment of pain. Substance P was also noted to affect hypothyroidism. I found another Substance P antagonist on another web site. Search Google for "FM and Substance P antagonists". I am hopeful about this.