HCRT and narcolepsy: According to Baier et al. [14], the restoration of olfactory function through orexin-A administration, as evidenced by increases in olfactory performance metrics such as the TDI (Threshold Detection Index) score and PEA (2-phenyl-ethyl alcohol) thresholds, provides compelling support for the role of orexin deficiency in narcolepsy-associated olfactory dysfunction.