Serum levels of chemokines in adolescents with major depression treated with fluoxetine

BACKGROUND Major depressive disorder(MDD)is a global health issue that affects 350 million people of all ages.Although between 2%and 5.6%of affected individuals are adolescents,research on young patients is limited.The inflammatory response contributes to the onset of depression,and in adult MDD patients,symptom severity has been linked to chemokine levels.AIM To determine the differences in circulatory levels of chemokines in healthy volunteers(HVs)and adolescents with MDD,and assess the changes induced by fluoxetine consume.METHODS The 22 adolescents with MDD were monitored during the first 8 wk of clinical follow-up and clinical psychiatric evaluation was done using the Hamilton depresión rating scale(HDRS).The serum levels of monocyte chemoattractant protein-1(MCP-1),macrophage inflammatory protein(MIP)-1α,MIP-1β,interleukin(IL)-8,interferon gamma-induced protein(IP)-10,and eotaxin were measured in patients and HVs.RESULTS In all cases,significant differences were detected in circulating chemokine levels between patients before treatment and HVs(P<0.0001).All chemokines decreased at 4 wk,but only MCP-1 and IL-8 significantly differed(P<0.05)between 0 wk and 4 wk.In the patients,all chemokines rose to their initial concentrations by 8 wk vs 0 wk,but only IP-10 did so significantly(P<0.05).All patients experienced a significant decrease in HDRS scores at 4 wk(P<0.0001)and 8 wk(P<0.0001)compared with 0 wk.CONCLUSION Despite the consumption of fluoxetine,patients had significantly higher chemokine levels,even after considering the improvement in HDRS score.The high levels of eotaxin,IP-10,and IL-8 partially explain certain aspects that are affected in MDD such as cognition,memory,and learning.

Carrageenan-Induced Non-Painful Inflammation Reduces Voluntary Sucrose Consumption in a Two-Bottle Choice Paradigm: A New Model of Inflammation Induced Anhedonia

Anhedonia, the presence of diminished pleasure or decreased motivation for rewards is considered one of the core symptoms of depression. Studies have shown that anhedonia and reduced reward learning predict a poor prognosis with a higher prevalence of treatment failure among patients. Several mechanisms have been implicated in the onset and progression of depression;furthermore, an important amount of evidence supports not only the importance of the reward circuitry in the development of depressive anhedonia but also, that it is closely related with the presence of inflammation. In the current paper we show that 500 ul carrageenan administration in the right hind paw after deafferentation surgery leads to anhedonia, which is evident by a decrease in saccharine consumption in a two-bottle choice test;these findings suggest that carrageenan mediated inflammation is a reliable model of anhedonia that could lead to a better understanding of the immune-neural axis in motivation.