A stronger and more dangerous version of methamphetamine and fentanyl are helping drive America’s homeless crisis, with users quickly slipping into debilitating addiction and mental illness that makes it impossible for them to function in society.

“These two drugs come in such enormous quantities and have such staggering potency that they do the job far more masterfully than drugs have done it before,” author Sam Quinones, who detailed the opioid crisis in books such as Dreamland and The Least of Us, said in an interview with the Intelligencer last week. “So you have methamphetamine that is driving people to homelessness, and becoming incoherent and irrational and delusional and paranoid.”