This is from CNN.
Also detailed in the declassified file was Rehnquist's 1981 hospital stay for treatment of back pain and his dependence on powerful prescription pain-relief medication.
The FBI investigated his dependence on Placidyl, which Rehnquist had taken for at least 10 years, according to a summary of a 1970 medical examination.
When Rehnquist checked into a hospital in 1981 for a weeklong stay, doctors stopped administering the drug, causing what a hospital spokesman at the time said was a "disturbance in mental clarity."
The FBI file, citing one of his physicians, said Rehnquist experienced withdrawal symptoms that included trying to escape the facility and discerning changes in the patterns on the hospital curtains. The justice also thought he heard voices outside his room discussing various plots against him.
The doctor said Placidyl is a highly toxic drug and that she could not understand why anyone would prescribe it, especially for long periods.