The role of neuroinflammation in juvenile bipolar disorder

A pathophysiological relationship has been reported between inflammatory processes, decreased levels of neurotrophins, increased oxidative stress and psychiatric disorders in both juvenile and adult ages. Moreover, this relationship remains unclear in juvenile bipolar disorder (BD). We performed a systematic literature review of studies reporting measurements of inflammatory markers, oxidative stress markers or neurotrophins in juvenile and young adult subjects with BD. Concordant findings showed that inflammatory markers are increased since the earlier stages of BD. A positive correlation between decreased levels of a peripheral brain‐derived neurotrophic factor and juvenile BD is controversial suggesting that those changes might occur only during the late stage of BD. No changes in central glutathione levels were reported in young adult age BD indicating that oxidative stress may be an outcome of long illness duration and repeated affective episodes. In conclusion, preliminary findings indicate that a certain relationship exists between inflammatory process and juvenile BD but evidence are insufficient to support a causal relationship. Adequately powered and prospective studies are warranted to clarify the role of inflammation, neurotrophins and oxidative stress in juvenile BD.