I remember reading a reference once to people using heroin in concentration camps because of the bleakness (same way there's been high usage rates in decaying urban areas going back to the beginning of urban areas), but in a Google search I couldn't find anything about it again--plus I had to question how they would get it in or continue to get it once interned... maybe it was the guards supplying (but then for what in return)?
This seems pretty doubtful considering the nazis themselves were in short supply of opium derived narcotics, because of Allied blockades.
If my understanding of the history is correct, these shortages of opium motivated the development of methadone.
I daresay that if the nazis had no dope, their concentration camps probably didn't either. This is before such a thing as what we understand as the 'drug culture' existed.
Opiates were probably not as restricted as they are nowadays in medicine - but i don't believe the black market existed in anything resembling today's drug trade. There were addicts in Europe in the 1930s and 40s, but until the 1960s my understanding is that the majority of these people became dependant as a result of medical prescription rather than recreational use or self medication.
I could be wrong though.
Having said that, Nazi doctors did all kinds of barbaric medical tests on people in various concentration camps - often to see what levels of pain, poison, abuse (etc etc etc) the human body could withstand before breaking under the pressure of interrogation - and/or dying. These were medical trials with very little ethical constraint.
I wouldn't be at all surprised if tests were conducted on people made physically dependant - then forced to withdraw from - narcotics.
Third Reich doctors are known to have used all kinds of drugs such as deliriants and even mescaline in torture/interrogation experiments.
The OSS/CIA mind control experiments of the 1940s onwards (such as the notorious MK-ULTRA program) were inspired and informed by some of these nazi doctors' "work" in torture and manipulation using psychoactive substances.
But as someone has already said, withdrawal would be the least of a nazi prisoner's problems, or perhaps the cause of their demise.
Most prisoners deemed unfit to work were hauled off to death camps.
What a bleak thread.