Finally, it must be mentioned that the dysfunction of the orexin system was demonstrated in common neuropsychiatric, neuroinflammatory, and neurodegenerative disorders such as schizophrenia, Parkinson’s disease, Alzheimer’s disease, Huntington’s disease, multiple sclerosis (MS), and amyotrophic lateral sclerosis (ALS) [232,244,245,246,247]. This evidence concerns the gene HCRT and early-onset autosomal dominant Alzheimer disease.