Sauchelli et al. (2016) demonstrated that Hcrt-1 levels significantly correlate with poor sleep quality in patients with anorexia nervosa. However, other research reported no significant link between decreased CSF Hcrt-1 levels and clinical sleep disturbances (Ogawa et al., 2022; Compta et al., 2009). Here, HCRT is linked to anorexia nervosa.