Three hours later, the 86th call: He was exposing himself in a Portland park. A judge authorized the blue paper. Officers returned him to the hospital.

By midafternoon, Mr. Burns sat in his police van in the hospital parking lot, juggling phone calls from social workers, hospital staff, beat cops and members of his behavioral unit. In the rush to get the young man committed, no one remembered to grab the blue paper, which was still sitting on a desk at the police department.

Mr. Burns, who has worked with homeless people around the country for three decades, massaged his aching temples. “Everyone is spinning,” he said. “The person on meth has no idea what’s going on, and neither do we. At the end of the day, nothing really gets better. It’s one big cyclone of misery and confusion.”

A slow killer

People who use meth claim it gives them “superpowers”— great sex, lots of energy, supreme confidence. That is because meth stimulates the brain to release unparalleled amounts of reinforcing, feel-good neurotransmitters such as dopamine.

In rural Maine, workers cobbling together a livelihood with repetitive shift work use meth to stay awake. In Portland, people living in shelters or encampments say meth keeps them alert against theft and sexual assault.

“Often meth use is a story of trying to survive,” said Dr. Kevin Sullivan, who lugs a cart of emergency medical supplies for Bayside patients living on the streets.

When meth euphoria wanes, many people keep using to reignite the high. Then they can’t sleep or eat for days. They forget to drink water. During the final stage of a binge, known as tweaking, they may become erratic, ranting, vicious. Paranoia and hallucinations seize them.

When people get pounded by meth withdrawal — sweating, depression, agitation — they may self-soothe with fentanyl to help them, in street talk, “land.” Conversely, when fentanyl users go into withdrawal, they may grab meth.