"The disease of addiction is crazy," the artist shared.
Macklemore said the September 2020 episode of the podcast, in which Shepard revealed that he relapsed after celebrating 16 years of sobriety, made him cry.
"I really, really resonated with the episode," the 37-year-old songwriter expressed, adding how amazed he was by Shepard's ability to be "vulnerable and honest" with his fans.
"It was within two months of my COVID relapse, and the disease of addiction is crazy," said Macklemore, whose real name is Benjamin Haggerty.
The Grammy winner furthered that speaking about the struggles with sobriety "lets other people feel that they're not alone."
"It made me feel, as someone that had relapsed again, like a month or two before, that I'm not alone," he said.