Abstract

OBJECTIVES: To explore the relationship between inflammation and neuronal metabolism in bipolar disorder (BD) by evaluating the neurochemical effects of the tumor necrosis factor-alpha (TNF-alpha) antagonist infliximab among individuals with bipolar depression METHODS: This is a post-hoc, exploratory analysis from a 12-week, randomized, double-blind, placebo-controlled trial with infliximab for adults with bipolar depression. We assessed the effects of infliximab on concentration of metabolites in the prefrontal cortex, using proton-magnetic resonance spectroscopy (1H-MRS), as well as its association with clinical outcomes (i.e. depressive symptom severity and cognitive function).RESULTS: Eighteen participants in the placebo and 15 in the infliximab group were included in this analysis. In the pre-specified primary outcome, there were no significant effects of treatment on prefrontal concentrations of N-acetylaspartate (NAA; p=0.712). In the secondary analyses, there was a significant treatment by time interaction for glutamate (Glx; p=0.018), indicating that Glx levels decreased in infliximab-treated patients, relative to placebo. Treatment group significantly moderated the association between changes in Glx levels and changes in a neurocognitive test (i.e. Digit Symbol Substitution Test; p=0.014), indicating that in infliximab-treated participants reductions in Glx were associated with cognitive improvement.CONCLUSIONS: Treatment with infliximab did not affect prefrontal NAA concentration in adults with BD. Exploratory analysis suggested a potential effect of treatment on the glutamate system, a finding that should be confirmed and validated by additional studies.

View details for DOI 10.1016/j.jad.2020.11.128

View details for PubMedID 33296798