Targeting inflammation to influence mood following spinal cord injury: A randomized clinical trial

Background: the purpose of the present study was to examine the efficacy of targeting inflammation as a means of improving mood following spinal cord injury (sci) and explore the potential mechanisms of action. methods: the study was a randomized,parallel-group,controlled,clinical trial (nct02099890) whereby 20 participants with varying levels and severities of sci were randomized (3:2) to either the treatment group,consisting of a 12-week anti-inflammatory diet,or control group. outcome measures were assessed at baseline,1 and 3 months,and consisted of ces-d scores of depression,markers of inflammation as assessed by various pro- and anti-inflammatory cytokines and several amino acids related to depression. results: a significant group × time interaction was found for ces-d (center for epidemiologic studies depression scale) score (p = 0.01),the trp/lnaa (tryptophan/large neutral amino acid) ratio (p = 0.04),the composite score of pro-inflammatory cytokines (p = 0.04),il-1β (interleukin-1 beta) (p = 0.04),and ifn-γ (interferon gamma) (p = 0.03). pearson's r correlation showed significance between the {increment}il-1β and both the {increment}ces-d score (r = 0.740,p < 0.01) and the {increment}kyn/trp (kynurenine/tryptophan) ratio (r = 0.536,p = 0.02). the {increment}kyn/trp ratio was also significantly correlated with the {increment}ces-d score (r = 0.586,p = 0.01). mediation analysis showed that the relationship between the {increment}kyn/trp ratio and the {increment}ces-d score was mediated by the {increment}il-1β. subgroup analysis showed that participants with high ces-d scores had significantly higher concentrations of il-1β,and all correlations were maintained or strengthened within this subgroup. conclusions: overall,the results demonstrated the effectiveness of targeting inflammation as a means of improving mood in sci,with potential mechanisms relating to the reduction in il-1β and improvements in levels of neuroactive compounds related to the kynurenine pathway. due to the limited sample size,results should be interpreted with caution; however,they are worthy of further examination due to the potential impact of inflammation on depression. trial registration: clinicaltrials.gov id: nct02099890. © 2015 allison and ditor.