Spector, 69, was sentenced two months ago to 19 years to life in a Los Angeles prison following his re-trial for Clarkson's death. The first ended in a mistrial because the jury couldn't agree on a verdict.
"He's doing fair, at best, if not worse than fair. He's not doing great," Spector's publicist Hal Lifson told BBC 6 Music News.
"He's in a horrible situation with virtually nothing to do all day," Lifson said. "Phil Spector was always a highly productive, creative person and now he's in a 5-by-9 foot cell with no windows and maybe a half hour outside to walk around. ... It's essentially solitary confinement. ... He doesn't have computer access, he only recently got a little TV. It's a terrible existence for a millionaire record producer who lived in mansions and most recently in a castle, a 35-room home. It's a huge, huge change of life for Phil Spector and a devastating turn in his life."
Spector's legal team suggested during the producer's trials that Clarkson shot herself, either by accident or because she was depressed regarding her stalled acting career.