Alex Trebek has experienced "massive attacks of great depression" throughout his battle with pancreatic cancer.
The 'Jeopardy!' host first revealed he was suffering from stage four pancreatic cancer in March 2019, and one year on from his diagnosis, he has taken to social media to give an update on the past year of his health journey.
In a video posted to Twitter, he said: "The one-year survival rate for stage IV pancreatic cancer patients is 18 percent. I'm very happy to report I have just reached that marker. I'd be lying if I said the journey had been an easy one.
"There were moments of great pain, days when certain bodily functions no longer functioned, and sudden massive attacks of great depression that made me wonder if it really was worth fighting on."
Alex, 79, says he "brushed aside" his mental health struggle for the sake of his wife Jean, whom he credits with "giving her all to help [him] survive".
The game show host also claims he needed to be strong for other cancer sufferers who have looked to him as an "inspiration and cheerleader".
He added: "But I brushed that aside quickly because that would have been a massive betrayal - a betrayal of my wife and soulmate, Jean, who has given her all to help me survive.
"It would have been a betrayal of other cancer patients who have looked to me as an inspiration and a cheerleader of sorts of the value of living and hope. And it would certainly have been a betrayal of my faith in God and the millions of prayers that had been said on my behalf."
And Alex concluded his video by insisting he remains "positive" about the outcome of his health journey, as does his oncologist.
He explained: "[My oncologist] said 'Alex, even though the two-year survival rate is only seven percent,' he was certain that one year from now the two of us would be sitting in his office celebrating my second anniversary of survival. And you know something? If I, no, if we - because so many of us are involved in this same situation - if we take it just one day at a time with a positive attitude, anything is possible."