Deadwood mastermind David Milch revealed Tuesday that he has been diagnosed with Alzheimer’s Disease.

“As best I understand it, which is minimally, I have a deterioration in the organization of my brain,” he tells Vulture. “And it’s progressive. And in some ways discouraging. In more than some ways — in every way I can think of.”

Milch says he first noticed symptoms of the degenerative disease five years ago, when his recall grew increasingly imperfect and his temper flared more often than normal. Doctors delivered the news last year after he underwent a brain scan. The cast and crew of his HBO Western, which will end with a wrap-up movie premiering on May 31, reportedly are aware of Milch’s condition.

Milch penned the two-hour revival; it picks up 10 years after the events of Season 3, which wrapped in 2006. “Former rivalries are reignited, alliances are tested, and old wounds are reopened, as all are left to navigate the inevitable changes that modernity and time have wrought,” according to the official logline.

The prolific scribe’s TV work includes some of the medium’s most critically acclaimed series: In addition to creating Deadwood, he co-created NYPD Blue and worked on L.A. Law and Hill Street Blues, among other dramas. Milch says he will continue writing, though did not offer Vulture details about future projects.