The literature search was conducted using the MeSH terms “bipolar disorder,” “mood disorder,” “manic disorder,” “mania,” and the modifiers “youth,” “treatment,” “antipsychotics,” “inflammation,” “CRP,” “IL-6,” “NF-kB,” “steroids,” “cortisol,” “glucocorticoids,” “sex steroids,” “testosterone,” “androgens,” “estradiol,” “body composition,” “frailty,” “muscle mass,” or “fat mass,” The original PubMed search was conducted for references published between January 1, 1950 and February 15, 2017. This evidence concerns the gene IL6 and bipolar disorder.