Elizabeth Vargas Back In Rehab; "I'm ashamed."

20/20 anchor Elizabeth Vargas is back in rehab for alcoholism. The 51-year old told Page Six she decided to go back into treatment over the weekend. Vargas first entered treatment last fall. She and her husband, Mark Cohn ("Walking In Memphis" songwriter) are going through a divorce. Cohn is reported to have had an affair while Vargas was in rehab the first time. Vargas recently signed a new deal with ABC. Suits there say they're standing by her.

Paging Dr. Drew?