Depression and anxiety symptoms at TNF inhibitor initiation are associated with impaired treatment response in axial spondyloarthritis

OBJECTIVES: Depression and anxiety are associated with more severe disease in cross-sectional studies of axial spondyloarthritis (axSpA). We examined the association between baseline symptoms of depression or anxiety and response to TNF inhibitors (TNFi) in axSpA. METHODS: Biologic naïve participants from a national axSpA register completed the Hospital Anxiety and Depression Scale (HADS) before initiating TNFi. Symptoms of anxiety and depression were each categorized as moderate–severe (≥11), mild (8–10) and ‘none’ (≤7), and compared against change in disease indices [BASDAI and AS Disease Activity Score (ASDAS)] over time and time to treatment discontinuation using marginal structural models. Inverse-probability weights balanced baseline age, gender, BMI, deprivation, education and baseline values of respective disease indices. RESULTS: Of the 742 participants (67% male, mean age 45 years), 176 (24%) had moderate–severe and 26% mild depression; 295 (40%) had moderate–severe and 23% mild anxiety. Baseline disease activity was higher in higher HADS symptom categories for both depression and anxiety. Participants with moderate–severe depression had significantly poorer response compared with those with ‘none’ throughout follow-up. At 6 months, the difference was approximately 2.2 BASDAI and 0.8 ASDAS units after balancing their baseline values. Equivalent comparisons for anxiety were 1.7 BASDAI and 0.7 ASDAS units. Treatment discontinuation was 1.59-fold higher (hazard ratio 95% CI: 1.12, 2.26) in participants with moderate–severe anxiety compared with ‘none’. CONCLUSIONS: Symptoms of depression and anxiety at TNFi initiation are associated with poorer treatment outcomes. Targeted interventions to optimize mental health have potential to substantially improve treatment response and persistence.