In the Austrian prison Graz, a randomized group of 64 prisoners (12,5%
out of 512 total) was selected to investigate patterns of drug abuse.
From this group, 60 consented to drug-screening in urine. While opiat
es, cocaine, alcohol and amphetamines screened negative. cannabis (in
8,4%) and benzodiazepines (in 20%) had positive results.