Effect of depressive symptoms on treatment response in patients with axSpA: data from the RABBIT-SpA register.

Objectives: This analysis aimed to evaluate the effect of depressive symptoms on treatment outcomes in patients with axial spondyloarthritis (axSpA), focusing on low disease activity (LDA) and inactive disease (ID) at 3 and 6 months after the start of a new systemic therapy.

Methods: This analysis used data from the longitudinal, observational RABBIT-SpA register. Depressive symptoms were assessed using the WHO-5 Well-Being Index, with scores below 29 indicating moderate-to-severe symptoms. The treatment outcomes LDA and ID, based on the Axial Spondyloarthritis Disease Activity Score with C-reactive protein, were evaluated after 3 and 6 months. Logistic regression models adjusted for confounding variables, selected via a directed acyclic graph, were used to assess the relationship between baseline depressive symptoms and treatment outcomes. Multiple imputation was used to handle missing data.

Results: A total of 1755 patients with axSpA were included in the analysis. Moderate-to-severe depressive symptoms were present in 29% of patients at baseline. Fewer patients with moderate-to-severe depressive symptoms reached LDA or ID at 3 months and 6 months compared with those with no or mild symptoms. Logistic regression analysis showed that depressive symptoms were associated with lower odds of reaching LDA or ID at both time points.

Conclusion: Depressive symptoms have a significant and independent negative effect on treatment response in patients with axSpA, particularly in achieving LDA and ID. These findings highlight the importance of routine mental health screening and treatment of depressive symptoms in axSpA management to optimise disease outcomes.