A Study On The Relationship Between The Plasma Level Of Interleukin-6 And The Symptom Of Somatic Pain In The Depression

Background:In the psychiatric clinical work,more and more depressive patients report somatic pain in different regions and degree.A large number of experience and researches suggest the depressed patients with somatic pain are more difficult to diagnose,treat and improve prognosis than the simple depression.The pathophysiological mechanisms about comorbidity is not clear thoroughly. As is known to all,interleukin-6 may be involved in the depression.Recently, a series of results display that interleukin-6 may contribute to pain-related diseases.To explore whether IL- 6 is associated with the pain symptom of body in the depression,we design this trial to measure the serum interleukin-6 level in the depressed patients with somatic pain,and then compare which with the simple depression.Objective: To investigate the serum level of interleukin-6 and its influence on the pain symptom of body in depressed patients.Methods: The researcher through professional training finished HAMD-17 and Visual Analogue Scale(VAS) assessment,then enrolling 32 depressed patients into the painful group and 31 subjects into the single group according to the definition of somatic pain. The control group was 30 healthy individuals.The serum level of interleukin-6(IL-6) was measured with the method of enzyme-linked Immuno-sorbent assay.Results:(1)The total score of HAMD-17 and anxiety factor score in painful group were significantly higher than those in single group((23.4±4.0)scores vs(20.6±2.8)scores,(9.4±1.7)scores vs(8.1±1.2) scores;t=3.297, 3.627;P=0.002,0.001 respectively).(2)The serum level of IL-6 was significantly higher in depression with somatic pain than those without somatic pain which was higher than the healthy controls((14.5±2.3) pg/ml vs(12.5±2.2)pg/ml,(12.5±2.2) pg/ml vs(11.3±2.3) pg/ml);d=2.0,1.2;P=0.001,0.041 respectively).(3)There was a positive relationship between plasma level of IL-6 and scores of VAS in depressive patients with pain symptom of body(r=0.382,P=0.031).Conclusion: The serum level of IL-6 was increased in the depression with somatic pain compared with those without somatic pain,which suggested that the elevated IL-6 may be involed in the pathophysiological mechanisms of somatic pain symptom in major depressive disorder.