Effect Of Pain-related Anxiety And Pain Catastrophizing In Comorbidity Of Depression And Chronic Pain

Objective : Although a growing body of research has studied the comorbidity of depressive disorder and chronic pain,research on the role of pain-related anxiety and pain catastrophizing on this specific kind of patients is limited.The present study aimed to investigate the mediating effects of pain-related anxiety and pain catastrophizing on these patients with comorbidity.Methods:One-hundred and forty participants were included in this study and divided into three groups according to the Diagnostic and Statistical Manual of Mental Disorders,namely,the comorbidity group（depression patients with chronic pain,n =45）,depression group（depression patients without chronic pain,n = 47）,and control group（healthy controls,n = 48）,The Hamilton Depression Rating Scale-24 and Hamilton Anxiety Rating Scale-14 were administered by a clinical psychiatrist to evaluate the severity of depression and anxiety,respectively.Beck Depression Inventory-Ⅱ（BDI）and Beck Anxiety Inventory（BAI）were conducted by patient self-report to assess symptom severity.Pain intensity numerical rating scale（PI-NRS）was to assesses pain intensity.Pain Catastrophizing Scale（PCS）and Pain Anxiety Symptoms Scale（PASS）were used to estimate pain-related negative thinking.Results:The results of Repeated-measure ANOVA showed that PASS and PCS scores were remarkably different among the three groups,particularly in the comorbidity group.Pearson correlation analysis revealed that the self-reported depression and anxiety symptoms of patients had positive correlations with fear of pain,physiologic anxiety,and total PASS score.The patients’ helplessness,magnification,rumination,and total scores in PCS had positive correlations with depression and anxiety symptoms.Stepwise regression analysis results showed the total PCS score and high monthly income level,and BDI score had positive relationships with PASS score（β=0.678,t=9.025,P< 0.001;β=0.194,t=2.719,P=0.008;β=0.204,t=2.662,P=0.009）,and male sex had a negative relationship with PASS score（β=-0.169,t=-2.447,P=0.016）.Total BDI score and disease course ≥ 1 year had positive effects on PCS（β=0.261,t=2.646,P=0.010;β=0.291,t=3.024,P=0.003）,whereas years of education（< 12 years）had a negative effect on PCS（β=-0.240,t=-2.562,P=0.012）.Finally,the mediator pathway revealed the remarkable mediating effect of PCS and PASS scores on the relationship between predictive factors and depression symptoms.Conclusion:（1）Pain related catastrophic thinking and anxiety were more severe in the comorbidity group than in patients without chronic pain and healthy group.（2）Gender,course of disease,monthly income,years of education and pain intensity were correlated with pain related anxiety and pain catastrophization thinking,which might be risk predictors of depressive comorbidities of chronic pain.（3）Catastrophizing of pain may mediate depressive symptoms and pain-related anxiety.