This study was done at a community college. Using muscle testing a spinal segment was found to be associated with an emotional response. Students were then adjusted while exposed to a fearful stimulus. It was found that the adjustments reduced the level of anxiety. Each student's heart rate and report of fear was taken before, during and after viewing a "phobogenic stimulus" (fear evoking item ex. spider). Spinal adjustments were performed while the student was experiencing fear. After the chiropractic adjustment, the phobic test was performed again.
The researchers reported: "spinal manipulation significantly de-creased the intensity of emotional arousal reported by phobic subjects."
Peterson KB. J Manipulative Physiol Ther. 1997 (Nov-Dec);20 (9):602-606