This CPB has been revised to state that brexanolone (Zulresso) is considered experimental and investigational for treatment of neurodegenerative disorders. This CPB has been updated to add a precertification requirement note for Zulresso therapy. This CPB has been revised to remove the requirement "member does not have current substance or alcohol use disorder" from criteria for initial approval. This CPB was updated with the following: (i) created subheaders, and (ii) reorganized the policy format and subheader locations.