Socialite Paris Hilton is so "emotionally distraught and traumatised" since being sentenced to 45 days in jail, she cannot attend a civil trial which was set to start next Monday.
Psychiatrist Dr Charles Sophy has filed a legal declaration in which he claims Hilton is "not capable of any meaningful participation" in the civil case brought against her by diamond heiress Zach Graff.
Graff has launched her $10m (€7.4m) suit against Hilton because of the "vicious lies" the hotel heiress spread about her that ended up being printed in the New York Post newspaper.
However, Sophy writes that Hilton's state of mind after being found guilty of violating her probation by driving with a suspended license means she "cannot effectively respond to examination as a witness or provide any significant input into her defence."
The judge has postponed the trial until 22 August, reports website TMZ.com.