Chances are you have a relative or know someone with Alzheimer’s disease, with symptoms causing problems with memory, thinking, and behavior that worsen gradually over the years. Even greater is the likelihood that you’ve read about the disease, which in time becomes so severe that patients are transformed into unresponsive husks of their former selves. Everything you know comes from observation or reading doctors' accounts — but do you really know Alzheimer’s?

Well, now you can begin to understand from the inside out. Greg O’Brien, an award-winning political writer and investigative reporter, was diagnosed with Alzheimer’s in 2010 and since then has made it is his mission to describe his condition. "Nobody likes to pull their pants down in public," O'Brien has said on any number of occasions. “But if that's what it takes to tell the story of Alzheimer's, that's what it takes." His intention in writing a memoir, On Pluto: Inside the Mind of Alzheimer's, is to raise awareness and inspire people to request that research money entrusted to the U.S. National Institutes of Health be directed toward finding a cure.

In March, Medical Daily interviewed O'Brien about his condition. He is a tall man, whose already gray hair has begun a second transformation to white. Thoughtful and perceptive, he was surprisingly expressive. If he struggled, on occasion, for a word or phrase, he was never at a complete loss. He appeared to want to answer as honestly as possible while also striving for humor.

What was your first sign of the disease?

I noticed about 15 years ago that I was having some memory problems. I’d find myself in places that were familiar and I didn’t understand and I’d start not to recognize people. It was troubling, but I fought through it. And as my sister knows, who’s a nurse, I was able to fight through it, and then I had a serious head injury and after that I just couldn’t do it anymore. And I went to the doctors and they didn’t really do Alzheimer’s diagnosis in those days, but they put me on a new pill that had just come out called Aricept.

Did the medicine work?

It’s a Cadillac. I was one of the first people on Aricept. And they put me on a small dosage ... and it would help me through, but then I needed more. So I asked for a little more. I got to the point where the doctors said, We can’t give you anymore because [you’ve reached] the legal limit.

So that medicine stopped working for you? Did the doctors explain why?

What the doctors will tell you is a head injury will bring on Alzheimer’s and dementia … I’ll put it in layman’s terms: when you’re under stress and your head gets hit, there’s a spigot that turns on these amyloids … [but that] spigot gets stopped open. So it clogs up the brain and it begins the deterioration process. So they said that in my case, that had accelerated it. And then they gave me the gene test and said I have one of the Alzheimer’s disease gene markers, APO4. Both my grandfather and my mother had it, and with my serious head injury looking at all those things, they said, “You’re not getting out of this.”

(Greg still takes Aricept as well as Namenda, to help slow the rate of decline in thinking, and Celexa, and sometimes Trazodone.)

How old are you?

I’m 64 in two weeks.

Do you know what stage of Alzheimer's you are in now?

Well, 60 percent of my short-term memory is gone in like 30 seconds. I see hallucinations that are scary, and I don’t know how to explain it, but it’s the same thing that my mother saw, just scary things that just come at you. My mother used to talk about them all the time, and I know what they are now. It’s part of this stage of Alzheimer’s.

Can you give an example?

There was a time in Boston where we went to get our car, and we were in Quincy Market, and it was one o clock in the morning and I [saw] someone had pulled the metal — you know those metal gates? — down and I [thought], "We’re screwed, how are we getting home?" And I walked toward it and it disappeared. There are times I’ve woken up where I haven’t recognized my wife.

Everyday, 24/7, you have to fight through it, it never goes away. When you get up in the morning, it’s like someone has taken your brain, it’s an old file cabinet and spread all the files over the floor, and you have to put things back together.

What was the previous stage like?

The beginning of forgetfulness, short-term memory loss. It wasn’t as horrific as this phase. There were no hallucinations. I generally kind of knew where I was. I did have significant short-term memory loss, but not the 60 percent that’s lost right now. The rage was under control. My judgment and filter were OK. But you become more childlike. Now, because I’m Irish, I always look for the humor in it. I enjoy becoming more childlike. You kinda enjoy the potty talk. You get into that.

Why have you written a book about your condition?

I was there when my mother died, and I saw what happened to my grandfather, and I was there when he died, and as a reporter I just said: "You know, dammit, this is gonna stop. And I’m gonna write about it."

How does Alzheimer’s kill people?

Public health officials estimate that as many as 5.1 million Americans currently have Alzheimer's disease, which accounts for anywhere from 50 to 80 percent of all dementia cases. Aging is the greatest risk factor for most forms of Alzheimer’s, with the likelihood of developing the disease doubling every five years after you reach the age of 65. Alzheimer’s is the sixth leading cause of death in the U.S., and usually takes a patient’s life about eight years after symptoms first become noticeable to others, though survival can extend up to 20 years. The way Alzheimer’s causes death is by spreading to and incapacitating the parts of the brain that control breathing; essentially, a patient suffocates to death. More often, though, pneumonia or an infection (both difficult to treat when a patient is unresponsive) is what eventually kills those who have the disease.

What happens inside the brain of Alzheimer’s patients is the development of two abnormal structures that stealthily spread, destroying brain cells in their wake. Plaques are accumulations of a protein fragment called beta-amyloid; these build-up like sediment in the spaces between nerve cells and interfere with messaging. Tangles, the other abnormal structure caused by the disease, are twisted fibers of a protein called tau that amass inside the cells themselves. Most people’s brains show evidence of plaques and tangles as they age, but patients with Alzheimer's develop far more and do so in a very particular pattern, beginning in the areas important for memory before spreading to other regions.

Drugs may help some sufferers manage their symptoms, but so far no drug has been created to truly slow the progression of disease. To understand more about Alzheimer's or ways you can help — by participating in a research trial, emailing your representative in Congress, or donating money — begin here.