The Sleep Files: Altered States
- Blwyddyn: 1998
- Gwlad: United Kingdom
- Genre: Documentary
- Stiwdio: Twenty Twenty Television, Discovery Communications
- Allweddair:
- Cyfarwyddwr: Joseph Bullman
- Cast: Nigel Anthony, Rosalind Cartwright, Denise Corke, Michel Corke, Penny Corke, Floyd S. Cornelison, Jr., M.D.