In that case - they are REALLY STUPID, if they are still blowing positive
You would be surprised by the number of people who are ready to jeopardize everything. It's in the mind, they read about how the system can be beaten and when the testing is routine and maybe it worked once , they can do it again.
I wouldn't call it an addiction , but , alcohol used to be a big part of a pilot's life out here. With the zero tolerance policy, a lot of them are unable to change their habits .With the rise in BA + , the DGCA is taking a long needed tough stand . Gone are the days of a slap on the wrist , recently one of our captains lost his ATPL and suspended for five years with a possibility of criminal proceedings in the future.
They need help and it's more prevalent globally than you think.