Active brain inflammation appears to be one of the causes driving anxiety and depression in patients with relapsing-remitting multiple sclerosis (RRMS), finds an Italian study published in the journal Neurology. RRMS is the most common form of the disease when patients are initially diagnosed.
Multiple sclerosis patients are often diagnosed with mood disorders. This is not only because of the burden of the disease itself, some studies have suggested, but also due to neuroinflammation. Indeed, inflammation likely contributes to psychiatric disorders, including depression.
The study, “Neuroinflammation drives anxiety and depression in relapsing-remitting multiple sclerosis,” evaluated whether inflammatory mediators may cause the mood of RRMS patients to fluctuate.
To find out, researchers at Rome’s Tor Vergata University Hospital assessed the psychiatric status of 405 RRMS patients and determined inflammatory activity in the brain via magnetic resonance imaging (MRI). Researchers also assessed levels of pro-inflammatory mediators in the cerebral spine fluid (CFS) of 111 patients who had not received any therapy.
The team found higher rates of anxiety and depression in patients whose MRI scans revealed signs of inflammatory activity. Researchers also observed that radiologic activity was an independent predictor of depression in RRMS patients.
“No significant differences were observed between relapsing patients and those with only radiologic activity, highlighting the subclinical inflammation effects on mood symptoms,” researchers reported.
Treatment with anti-inflammatory drugs such as methylprednisolone, was found to influence patients’ psychological symptoms, reducing anxiety and depression. The scientists also found that levels of pro-inflammatory mediators in the CFS samples correlated with brain inflammation, and consequently with the severity of psychological symptoms.
Of the 327 patients who showed no signs of disease activity at the beginning of the study, 40 experienced clinical relapse and 53 had signs of subclinical MRI reactivation over the ensuing six months. After analyzing clinical and radiological data, researchers found that traces of anxiety could predict early disease reactivation in remitting patients.
Overall, these results demonstrated that neuroinflammation is associated with mood symptoms in MS, and that fluctuations in the psychological profile of patients with RRMS may reflect subclinical inflammatory alterations.
“Investigating how inflammation influences the neuropsychological performance might provide crucial insights into psychiatric pathophysiology, beyond MS-related mood symptoms,” researchers concluded.