Depression in those who are ill is 5–10 times more common than in the general population. Increasing evidence implicates bidirectional biological mechanisms linking mood disorders and medical conditions.1 Depressive symptoms are significantly more common in rheumatoid arthritis (RA) than in the general population. Conservative estimates suggest major depressive disorder in between 13% and 17% of patients with RA. However, prevalence exceeding 40% has been reported in a recent study, with up to 11% of patients experiencing suicidal ideation.1 Major depressive disorder is an independent risk factor for both work disability and mortality in patients with RA.2

Cytokine dysregulation is central to the pathogenesis of RA with functional implications for breach of tolerance and autoimmunity, subsequent inflammation and articular dysfunction.3 Tumour necrosis factor (TNF), in particular, appears to be of pivotal importance in pathogenesis, based …