A new study has revealed that subclinical intrathecal inflammation influences anxiety and depression in relapsing–remitting multiple sclerosis (RRMS), and has prognostic relevance in patients with this condition. An increased incidence of depression and anxiety has been described in RRMS; however, the origin of these mood alterations was unclear. In new research published in Neurology, investigators carried out psychiatric evaluations and measured intrathecal inflammation with MRI in 405 patients with RRMS. In a subset of 111 patients, the team also examined the levels of proinflammatory cytokines in the cerebrospinal fluid. Significant reductions in anxiety and depression were associated with reduced levels of intrathecal inflammation and proinflammatory cytokines. This finding suggests that fluctuations in mood could reflect subclinical neuroinflammation before relapse occurs.