According to an AP report on CNN, former Chief Justice William Rehnquist spent the Seventies on a powerful painkiller called Placidyl, finally going cold turkey during a 1981 hospital stay:

"Prior to his hospitalization, Rehnquist occasionally slurred his speech in his questions to lawyers at Supreme Court arguments. Those problems ceased when he changed medications, the doctor said." — via CNN

While hospitalized, a report from the FBI says, he hallucinated patterns on the hospital curtains and tried to escape in his pajamas, thinking that people in the hallway were plotting against him.

Ah, yes, a hallucinating Justice. The Seventies were a much simpler time.

Hat tip to Shakespeare's Sister for pointing out the family resemblance.