Loyalist supergrass Robert Stewart revealed he has been taking anti-psychotic drugs to keep him calm - but denied hearing "voices" that told him to implicate people in crimes.
The 37-year-old witness said he is now looking forward to "a good sleep" once he completes his evidence in a marathon Belfast Crown Court trial.
Trial judge Mr Justice Gillen said it looked as if "the end is in sight" for the evidence of the self-confessed terrorist who, along with his brother Ian, has implicated 14 others in a catalogue of UVF crimes.
The judge, sitting without a jury, told Stewart he should "look forward" to ending his evidence, possibly by mid-week.
Stewart quickly replied he was looking forward to "a good sleep, my lord".
Earlier yesterday Stewart admitted to the court that he has no answer to discrepancies in parts of his evidence in what he had initially told police and then the court.
The admission came as defence SC (State's Counsel) Philip Magee quizzed Stewart about his state of mind, and what he had told police and the court.
"The truth of the matter is," said Mr Magee. "You can't remember what the truth is."
Mr Magee continued to press Stewart, asking if his mind was telling him to put people forward as offenders who had never been mentioned before.
"Do you hear a voice ... put people in?" continued Mr Magee.
Denying the suggestion, Stewart maintained that "it was just an error".
However, Mr Magee repeated the question. He added: "Do you give people walk on and walk off parts, and that's the truth of it?"
"That's incorrect," said Stewart.
Although he denied "hearing voices", Stewart later admitted to defence barrister Mark Barlow that when he named one of his clients, David Smart, he had done so because there was "just something in my mind told me that he was there".
The case continues on Monday.