Higher Rates of Depression in Polymyalgia Rheumatica Are Strongly Associated With Poor Physical Function.

Abstract

Objective: To assess the prevalence of and risk factors for depression in a cohort of patients with polymyalgia rheumatica (PMR) compared with a cohort of participants without PMR (control group).

Methods: In a longitudinal cohort study, patients with recently diagnosed PMR (within 3 months of starting treatment) were recruited together with matched control subjects. Assessments were undertaken 3 and 21 months after initiation of steroid therapy. Mood was assessed using the Hospital Anxiety and Depression Scale (HADS) and the 36-item Short-Form Survey (SF-36) Mental Health (MH) scale, with scores ≥8 on the HADS and ≤56 on the SF-36 MH Scale indicating depression. Other data collected included current prednisolone dose, PMR-Activity Score, pain visual analog scale, SF-36, and Health Assessment Questionnaire Disability Index.

Results: Thirty-six subjects with PMR and 32 control subjects were recruited. At baseline, depression rates were significantly higher in PMR cases than in control subjects (22.2% vs. 3.1% and 25.0% vs. 0.0% as determined by HADS and SF-36 MH Scale, respectively). After adjusting for a previous diagnosis of depression, poor physical function (Health Assessment Questionnaire Disability Index) had the strongest association with depression determined by SF-36 MH Scale, with odds ratios of 8.19 (95% confidence interval, 1.06-63.46; p = 0.04) and 13.25 (95% confidence interval, 1.15-152.31; p = 0.04) at baseline and follow-up, respectively. Other significant associations with depression were identified with current prednisolone dose, disease activity (PMR-Activity Score), pain (pain visual analog scale and SF-36 Bodily Pain Scale), and fatigue (SF-36 Vitality Scale).

Conclusion: Depression affects up to 1 in 4 patients with PMR. The strongest association is with poor physical function, highlighting the psychological impact of physical limitations in PMR and the need to address comorbid depression to optimize patient outcomes.