Susan Boyle has "no underlying mental issues" and is simply exhausted, Amanda Holden has insisted.
The 48-year-old has been recovering at the Priory clinic in north London after suffering what her brother described as an "anxiety attack" in the wake of her surprise defeat in the Britain's Got Talent final.
Show judge Amanda said she did not know how long Susan would spend at the Priory, but said doctors had assured show staff the singer was mentally sound.
She told GMTV: "I understand that we've spoken to her doctors and they really have reassured us that there are no underlying mental issues and it purely is just that she's knackered, for want of a better word."
Susan's brother Gerry Boyle said: "She's coming to terms with that now that she's no longer an anonymous face and I think what led up to it was the build up to the show and just psyching herself up for that and then wondering after the show 'where do I go now?'"
Simon Cowell's friend Max Clifford said he thinks Susan has a good future ahead of her.
"She will be given the care and attention that she deserves and I still believe that she's gonna be a huge star with huge album sales. Simon will make sure that if she wants to do this, she'll go in the studio with the most beautiful songs, the most beautiful arrangements and looked after and shielded so she can do what she really wants to do," he said.