Posttraumatic Stress Disorder, Depression, Anxiety, and Persistence of Methotrexate and TNF Inhibitors in Patients with Rheumatoid Arthritis

Objective: To examine the relationship of posttraumatic stress disorder (PTSD) with earlier treatment discontinuation and medication adherence in US veterans with rheumatoid arthritis (RA). Methods: Veterans Affairs (VA) administrative data (2005-2014) were used to define unique dispensing episodes of methotrexate (MTX) and tumor necrosis factor inhibitors (TNFi) for veterans with RA. Diagnosis codes were used to categorize patients into mutually exclusive groups: PTSD (with/without depression/anxiety), depression/anxiety without PTSD, and neither psychiatric diagnosis. Multivariable Cox proportional hazards models were used to evaluate associations between psychiatric diagnoses and time to disease-modifying antirheumatic drug discontinuation (lapse in refill >90 days). Multivariable logistic regression was used to examine associations of diagnoses with medication nonadherence (proportion of days covered <0.8). Results: There were 15 081 dispensing episodes of MTX and 8412 dispensing episodes of TNFi. PTSD was independently associated with a greater likelihood of earlier discontinuation of both MTX (hazard ratio [HR] 1.15 [1.10-1.21]) and TNFi (HR 1.20 [1.13-1.28]). Depression/anxiety had a comparable risk of discontinuation for both MTX (HR 1.14 [1.10-1.19]) and TNFi (HR 1.16 [1.10-1.22]). Depression/anxiety, but not PTSD, was associated with higher odds of MTX (odds ratio [OR] 1.12 [1.03-1.22]) and TNFi (OR 1.14 [1.02-1.27]) nonadherence. Conclusion: Veterans with RA and comorbid PTSD, depression, or anxiety had poor persistence of MTX and TNFi therapies. These results suggest that earlier discontinuation and low adherence to therapy among patients with RA with these psychiatric comorbidities may contribute to worse disease outcomes. Mechanisms by which these comorbidities contribute to lower adherence deserve further investigation and may lead to targeted interventions to improve disease outcomes.