Inflammatory cytokines and functional impairment in drug-free subjects with mood disorder

Abstract Objective To assess the association between peripheral levels of inflammatory cytokines and functional impairment in subjects with Bipolar Disorder (BD), Major Depressive Disorder (MDD) and population controls. Methods This was a cross-sectional study with a matched sample of drug-free young adults with BD ( n = 48), MDD ( n = 48) and population controls ( n = 48). Mood disorder was confirmed by a certified psychologist using the Structured Clinical Interview for DSM-IV (SCID-I). Functional impairment was assessed using the Functional Assessment Short Test (FAST). Serum levels of IL-6 and IL-10 were measured by ELISA. Results Peripheral levels of IL-6 and IL-10 were not significantly different between subjects with BD, MDD compared to controls. Higher levels of functional impairment were verified in subjects with BD and MDD compared to population controls ( p ≤ 0.001). In addition, IL-6 and IL-10 levels were positively correlated with functional impairment in subjects with BD (IL-6: r = 0.349, p = 0.016; and IL-10: r = 0.351, p = 0.016). Conclusion Inflammatory dysregulation was associated with functional impairment among drug-free subjects with BD. This finding suggests that inflammatory dysregulation may be involved in the neuroprogression of BD.