Depression intensifies pain

Data presented at the Annual Meeting of the European Neurological Society indicates that depression alters the processing of pain impulses as well as the sensitivity to pain.  New evidence of this relationship is being presented today by Italian experts in Berlin.  The anatomical cause of this connection may be due to the fact that, in part, the same regions and the same neurotransmitters responsible for the processing of emotional moods in the brain are also responsible for the processing of pain.  This in turn could point the way to new therapies with which pain and depression could be treated simultaneously.



The beginning of depression is the beginning of pain



Prof. Michele Tinazzi, compared the pain threshold as well as the pain tolerance of 25 patients – all with newly diagnosed and still untreated deep depression -- with the a healthy control group.  80 percent of the patients reported muscle-, joint- or head-aches occurring at the same time as or after the onset of depression. In the course of the study, both patients and the control group were subjected to standardized electrical pain impulses on both hands and feet.  The results showed that in all body areas measured, pain threshold as well as pain tolerance were considerably lower among all patients with depression than among those in the control group. Those with depression were significantly more sensitive to pain, in other words.



Brain regions used in common – common therapy approach



“Our study shows impressively that the purely physiological aspect of the pain threshold and the cognitive-emotional aspect of pain tolerance - i.e. how bearable or unbearable the pain seems to me - go hand in hand”, said Dr. Sandro Zambito Marsala (San Martino Hospital, Belluno, Italy).  “The most likely reason is that processing of pain and emotion share specific regions of the brain just as they share specific neurophysiological signal transmission pathways.”  Because the latter are substantially steered by serotonin and noradrenalin circuits, it stands to reason that serotonin-noradrenalin reuptake inhibitors simultaneously combat depression and pain and could therewith substantially simplify the therapy. “This hypothesis has to be verified first, however, through additional detailed studies”, cautions Dr. Zambito Masala.