Omileke et al. (2020) found significant positive correlations between plasma FGF21 levels and some cognitive parameters, such as word association in patients with BD, indicating that higher peripheral FGF21 might be associated with better cognitive performance. Moreover, FGF21 administration was proven to improve cognitive dysfunction and anxiety-like behavior in obese rats (Sa-nguanmoo et al., 2018; Wang et al., 2018). This evidence concerns the gene FGF21 and Anxiety.