Association between neutrophil to lymphocyte ratio and mood polarity in adolescents admitted to an inpatient psychiatric ward

Inflammatory processes are associated with mood disorders, but data on pediatric patients are scarce. The aim of this study was to investigate a possible association between elevated neutrophil/lymphocyte ratio (NLR) - a marker of inflammation and mood polarity (manic/depressed) in adolescents, admitted between 2010 and 2015 due to a mood disorder episode and to an adolescent inpatient ward. Electronic medical records of 305 patients (aged 10-19 years, 60.6% males) admitted during the study period due to a mood disorder episode were reviewed. Of these, 63 were diagnosed with manic episodes and 242 with depressive episodes. Multivariate analyses were used to compare NLR between and within the two groups, covarying for age, sex, and antipsychotic use. NLR was significantly higher in the manic episode group compared with the depression one. Moreover, in inpatients with multiple hospitalizations, the NLR was higher during their manic episodes than that during their nonmanic states. These results suggest that, as has been reported in adults with bipolar disorder, inflammatory mechanisms may be involved in adolescents' mood disorders as well, particularly in the manic episodes. Thus, clinicians may consider adding anti-inflammatories as part of the treatment of these patients.