Susan Boyle has branded rehab the "most frightening experience" of her life because she was cut off from her friends and family, banned from watching television, and unable to make any phone calls.
The Scottish singer checked into London clinic The Priory in 2009 shortly after coming second in TV contest Britain's Got Talent.
She was treated for exhaustion and insomnia at the rehab centre, but admits she hated her time there because she found the clinic a cold and terrifying place.
She tells British TV host Piers Morgan on his Life Stories show, "It was a bit of a scare, a scary time for me, being in a place like that. Although very therapeutic for some people, for people like me it was very scary. I thought 'I've nobody here I know, where's my family? Where's my friends? Do I have anybody left?' I wasn't allowed to see a television, or make a phone call, 'Where was everybody?' I just felt as though I'd been dumped, it was probably the most frightening experience I'd been through."
Boyle was also convinced her admission to rehab would destroy her dreams of a music career.
She adds, "I felt that the dream was over. A bit of a nightmare, but a turning point. For two days I was thinking about myself, what my position was, was I stable? I knew I was, I was just tired."