The news was confirmed just as BAFTA Cymru announced its plans to honor the 74-year-old funnyman at a ceremony in Cardiff on Oct. 2.
"Terry has been diagnosed with Primary Progressive Aphasia, a variant of Frontotemporal Dementia. This illness affects his ability to communicate and he is no longer able to give interviews. Terry is proud and honored to be recognized in this way and is looking forward to the celebrations," Jones' spokesperson said in a statement Thursday.
In addition to being a member of the famed Monty Python comedy troupe, Jones also helmed the classic movies Monty Python's Life of Brian and The Meaning of Life, and co-directed Monty Python and the Holy Grail with Terry Gilliam. He penned the screenplay for the 1986 fantasy movie Labyrinth, starring David Bowie, as well.
Although most of the Pythons are active on Twitter, none had commented on Jones' condition as of Friday morning.