Depressive symptoms are independently associated with pain perception in Colombians with rheumatoid arthritis.

AIMS To examine the relationships between psychosocial factors and reported pain in Colombians with Rheumatoid Arthritis (RA). METHODS One hundred and three RA patients [85% from the lowest socio-economic strata (SES) in the country] recruited from outpatient centers in Neiva, Colombia were administered the Disease Activity Scale (DAS) , which included a Visual Analog Scale (VAS) arthritis pain/activity rating, Zung Depression Scale, State-Trait Anxiety Inventory (STAI), Interpersonal Support Evaluation List-12 (ISEL-12), and Symptom Checklist-90 Revised (SCL-90R). MAJOR RESULTS VAS pain was not associated with socio-demographic or medical factors, but was negatively associated with ISEL tangible subscale (r=-0.22, p< 0.01; r=0.28, p<0.01). VAS pain was positively associated with Zung Depression Scale score (r=0.38, p<0.001), STAI-State and STAI-Trait Anxiety (r=0.23 and r=0.25 respectively, p's<0.01), SCL-90R Global Severity Index (GSI) and Positive Symptom Total (PST) (r=0.23, p<0.05 and r=0.29, p<0.01 respectively), and SCL-90R Somatization, Depression, and Anxiety subscales (r=0.30, p< 0.01; r=0.28, p<0.01; and r=0.20, p<0.05 respectively). A linear regression model showed that socio-demographic characteristics theoretically associated with pain perception (gender, age, and SES) explained only 2.4% of the variance of VAS scores (R(2)=0.02, p=0.49). The full model, including psychosocial factors significantly associated with VAS scores explained 18.9% of the variance in VAS pain perception scores (R(2)=0.19, p=0.02). The Zung Depression Scale score was the only factor independently associated with VAS pain, such that higher depression scores were associated with higher VAS ratings (β =0.13, p<0.01), controlling for gender, age, SES, STAI-State, STAI-Trait, ISEL tangible, SCL-90R GSI, and SCL-90R PST. CONCLUSIONS Depressive symptoms, anxiety, social support, and psychopathological symptom distress were associated with pain ratings, but only depressive symptoms were found to be uniquely associated with higher pain perception, taking into account socio-demographic characteristics and other psychosocial factors. Findings provide evidence for the need to assess and treat pain in RA in Colombia from a bio-psycho-social perspective. Future research is needed to determine effective depression screening and evidence-based interventions for depressive symptoms in RA patients in this socio-cultural context, as intervening in depression may decrease pain perception.