And who is going to pay for that???

HINT: it's not going to be the people who don't have a steady income.

If someone is mentally-ill enough to want to do drugs, then the welfare money that stops them from robbing for that drug money, is the least of society's problems. Society still created that drug addict person. Humans take drugs. Let them. Just stop subsidising dealers profits via prohibition. That is logical supply-and-demand economics. Making welfare recipients AND tax-paying workers submit to inhuman drug tests, is accepting more slavery when you should be accepting LESS. It also discriminates against cannabis users because that is by far the most long-term-detectable drug. There's an argument to be made for drug testing pushing people to cocaine, crack and even heroin, as these leave the body within maximum 48 hours (e.g. a weekend). Prohibition is the problem, not age-old humans-being-humans via drug-use. Stop accepting inhuman stress levels for money and scapegoating the mentally-ill because you're too chickenshit to fight the real exploiters.