Newly-released FBI files have given more details on William Rehnquist's dependence on strong painkillers while he was a US Supreme Court judge.
William Rehnquist was head of the Supreme Court for 19 years
Mr Rehnquist, who later became chief justice, is said to have been taking up to three times the prescribed dosage.
When he stopped taking Placidyl, he suffered withdrawal symptoms. The records say he tried to escape from hospital in his pyjamas.
Mr Rehnquist died in 2005, after 19 years at the head of the Supreme Court.
The FBI files were prepared in 1986 - years after his problems with the prescription drugs had ended - when Mr Rehnquist was nominated to the post of chief justice.
By then, he had been on the Supreme Court bench for 14 years.
Mr Rehnquist went into hospital in 1981, after his doctor tried to substitute Placidyl with other prescription drugs.
The judge - who appears to have suffered from chronic back pain and insomnia - had said the new medication was not strong enough, his doctor told the FBI.
The doctor is also reported to have said that Mr Rehnquist had taken Placidyl for about 10 years and that his increased consumption may have coincided with his wife's treatment for cancer.
The FBI files also reveal that his withdrawal symptoms included imagining that the CIA was plotting against him.
Mr Rehnquist's problems with painkillers were known around the time he went into hospital, but the FBI files released this week give more details.
They were released in response to requests made under the Freedom of Information Act.