With microdosing, however, “I could just see right away it was having this immediate, focusing sense of perspective,” Mr. Chabon said.

“If someone in a marriage is thinking better about themselves,” he said, “and is less prone to incredibly self-critical thinking, has more patience and is essentially more effective at being who they are, which is somebody you already love and think is wonderful, but they have this shadow over them that prevents them from being that person — if you find something that lifts that shadow, it’s going to be incredibly welcome.”

After a month, however, the bottle ran out. Terrified of being arrested, Ms. Waldman has not acquired or used the drug since, she said.

Occasionally she has found herself researching countries around the world that have more permissive drug laws, she said. “I mean, look, I’m happily married and not dead,” she said. “I’ve been prescribed so many medications over the years, and this worked better than any of them.”

As for negative reactions, the only one that comes to mind, she said, were the concerns of her youngest son, worried that “all the kids in my middle school are going to be saying, ‘Your mom’s on acid,’” Ms. Waldman said. “And then his older sister, who’s two years older, said: ‘No, this is a good thing. It might not be so great in eighth grade, but when you get to ninth grade, you’re going to be so cool.’”