Methadone "for pain" - there was that story about methadone being used as a torture for prisoners of the Germans in WW2.
First, they would secretly put small amounts in the prisoners food, and slowly increase the amount for about a month. Then they stop it.... withdrawals ARE torturous, you all know that.
Yes, also there was methadone being invented for Goering to travel with [he was a
morphine addict]. But this is just saying "it was used" for torture, not invented for torture.