At just 59 years of age, award-winning journalist Greg O’Brien was given the news no one ever wants to hear: You have Alzheimer’s disease and there is no cure.

But instead of falling into a pit of depression or despair, O’Brien turned his diagnosis with early-onset Alzheimer’s into an extraordinary new book that provides a stark, but ultimately uplifting insider’s view of what it’s like to live with advancing dementia.

In a Newsmax TV interview with “Newsmax Prime” host J.D. Hayworth, O’Brien — now 66 — says he knows what lies ahead for him, having watched both his mother and maternal grandmother die of the disease.

But those family experiences also pushed him to write his book, “On Pluto: Inside the Mind of Alzheimer’s.” In it, he candidly and eloquently chronicles his personal struggles with the condition, which strikes about 5 million Americans — a number projected to triple by 2050 as the nation’s 77 million baby boomers grow into old age.

A journalist by trade, O’Brien says he relied on his research and reporting skills to explore the “who, what, where, when, why, and how” of early-onset Alzheimer’s, which strikes before the age of 65 — about 5 percent of Americans diagnosed with the condition. By doing so, his book offers an extraordinary inside glimpse in the mind of Alzheimer’s and shares a handful of strategies that have helped him cope.

He says the hardest part of writing the book was coming to grips with the reality that the difficulties he’d experienced with his family were going to happen to him, as well.

“After I started with the horrific symptoms, I had the brain scans… and clinical tests that confirmed the diagnosis,” he explains, noting he also carries the so-called the Alzheimer’s gene — known as APOE4 — and that two serious head injuries “unmasked” the disease.

“Because I had a front-row seat with my family, I did go into the pity party and got angry with God. And then I said, OK, why don’t I use my muscle memory and so I decided to compile about 2,000 pages of notes of everything I was afraid I would forget.”

O’Brien’s experiences reflect the progress Alzheimer’s researchers have made in developing new ways to diagnose Alzheimer’s early in recent years. Among them: Brain scans that can identify neurological features that are hallmarks of the disease and genetic tests can identify the APOE4 gene linked to it — both of which helped confirm O’Brien’s diagnosis. There are also a handful of new drugs that have been developed in recent decades to slow the progression of Alzheimer’s.

But his experiences also underscore the grim reality that there is no cure or effective treatment for Alzheimer’s, and research into developing therapies that can stop or reverse the disease have been disappointing.

O’Brien says his book was inspired, in part, by his mother, who told him in the weeks before her death: “We all have a purpose in life. Go find it!” In fact, his deeply personal memoir is dedicated to her.

He says his journalistic training has allowed him step outside of himself, to an extent, to write about the indignities and challenges of Alzheimer’s with a certain level of subjective objectivity.

But that reporter’s stoic detachment has not always been able to shield him from the hardships he has experienced since his diagnosis seven years ago.

“There was a dark moment when I tried to take my life, because I’d seen what happened in my family and I didn’t want to take my family and friends there,” he tells Newsmax TV. “And the good Lord told me that’s my decision. So I’ve learned to walk in faith, hope, and humor. And my job is not to tell people what to believe in, but I have a strong traditional faith.”

O’Brien has also developed an extraordinary series of day-to-day strategies that have helped him manage the condition, which he says has robbed him of about 60 percent of his short-term memory and left him unable to recognize familiar places and people he’s known his whole life.

“Every morning before I get out of bed it’s like putting all the files in my brain back in place because overnight someone had taken the files and dumped them on the floor and I have to go through these steps  of what am I doing, who am I doing,” he explains.

“And there are times I go to the bathroom and I’ve brushed my teeth at times with hand soap and once gargled with rubbing alcohol. And so I write the names ‘rubbing alcohol,’ ‘mouthwash’ on some of the bottles now. You have to have strategies, you have to have faith, you have to have humor.”

O’Brien says he hopes “On Pluto” will help expand awareness of the impacts of Alzheimer’s, as medical researchers race to develop better diagnostic tests and treatments, with a “tsunami” of new cases projected over the next 30 years.

“Look, Bugs Bunny once said don’t take life too seriously because nobody gets out alive and my feeling is as the baby boomers press forward against this tsunami maybe we can try to do some good again,” says O’Brien, who is also fighting prostate cancer — a condition he has jokingly referred to as his “exit strategy,” which he says will keep him from spending his final days in a nursing home.

“If by talking to other people I can be the canary in the coal mine, then that’s given me purpose at a time when I feel I have no purpose, if that makes sense to you.”