It’s hard to imagine how anyone seeing the premiere of “Robin Williams: Come Inside My Mind” on HBO could have walked away from the documentary the same.

While I can’t say the film’s title does what it promises — gets us anywhere near what’s inside the comedian’s mind — his struggles with addiction and depression, with family life, with handling success are pretty clear.

And sad.

If you were hoping for more about the circumstances surrounding his death in 2014, there isn’t much about that either. But as with most celebrity-related deaths, it gives us reason to talk about difficult but necessary issues.

What we’ve learned since his death is, according to an essay by his wife, Susan Schneider Williams, the comedian had Lewy body disease and died by suicide “at the end of an intense, confusing, and relatively swift persecution at the hand of this disease’s symptoms and pathology.”

Temple Pettigrew of Acworth knows what that’s like.

“As tragic as Williams’ death was, Lewy body dementia is even more so,” Pettigrew said.

Not only is it often misdiagnosed as Parkinson’s disease, Lewy body, the second most common type of progressive dementia after Alzheimer’s, is as brutal as it is deadly.

RELATED: Alzheimer's disease is no laughing matter

Pettigrew, a registered nurse who watched her father-in-law’s death from Lewy body and has spent the past five years with Visiting Angels, the nation’s leading provider of in-home senior care, has seen it all. Nearly 40 percent of the agency’s clients have some form of dementia.

Temple Pettigrew, a registered nurse, lost her father-in-law to Lewy body dementia, the same disease comedian Robin Williams was diagnosed with before committing suicide in 2014. GRACIE BONDS STAPLES / GSTAPLES@AJC.COM

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Credit: undefined

According to Pettigrew, Lewy body affects more than a million Americans. Because it is marked by tremors early on, it is often mistaken for Parkinson’s, but there is a big difference between the two diseases.

Chief among them, she said, is how Lewy body changes a person’s personality and causes drastic mood swings as well as problems with perception. Patients also experience paranoia and hallucinations.

“The other big significance is they have very rapid decline, so it can be really shocking for a family,” she said. “Once diagnosed, the average patient has just five to eight years before they pass away.”

Pettigrew said it was devastating to watch the disease attack her father-in-law, Jim Pettigrew.

Within just four years of being diagnosed with Lewy body in 2000, he went from being an electrical engineer who could do anything, to a man who couldn’t feed himself, had no depth perception and was incontinent.

“It completely changed who he was,” she said. “One day we were a family who looked to him for guidance and the next our lives revolved around keeping him safe, from falling, from wandering away from home.”

Then in the winter of 2004, Jim Pettigrew died. He was 72 years old.

RELATED: Glen Campbell's death 'brings Alzheimer's out of the shadows.' Now what?

From that experience and her work with dementia patients since then, Pettigrew and her colleagues, Priscilla Hendry and Monique Lassitter at Visiting Angels, say joining a support group before the disease has time to progress is crucial.

“You have to plan for what is coming,” Pettigrew said.

Each week, Gracie Bonds Staples will bring you a perspective on life in the Atlanta area. Life with Gracie runs online Tuesday, Thursday and alternating Fridays.

Credit: The Atlanta Journal-Constitution

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Credit: The Atlanta Journal-Constitution

That’s the first step.

Here’s what else they say you should and shouldn’t do.

• Don’t ask open-ended questions such as “Do you want a glass of water?”

Do offer concrete choices to get concrete responses. Would you like water or coffee?

• Don’t wait on LBD patients hand and foot without making them get up and move. They will not try unless you ask.

Do say “Let’s go to the kitchen and try to pick out something to eat” and point to food in the refrigerator. If patients can’t walk, bring them pictures of food so they can point to their choice and interact. They may not be able to handle the mental juggling of making multiple decisions at once. You want to offer simple, step-by-step choices.

RELATED: Cost of Alzheimer's can devastate family's finances

• Don’t surprise someone with LBD from behind. They might see you as a threat and it could scare them.

Do walk past the patient so they can see you, then turn around and engage with them for a less confrontational greeting. Why? Patients with dementia have tunnel vision and can often only see in front of them. To understand the limited scope of their vision, make a telescope out of a piece of paper and put it to your eye.

• Don’t speak loudly in the face of a dementia patient. Dementia does not equal deafness.

Do speak in a clear, normal, warm tone of voice to start. The patient must take time to digest what you are saying. Often they do not understand every word, and they have trouble finding the right words or putting feelings into words. Call them by their name. This helps them maintain self-confidence and concentration.

Finally, be on the lookout for depression, they said. And, please, don’t hesitate to seek help.

If there was any way to get into the mind of Robin Williams, that might be the first thing he’d want us to know.

Find Gracie on Facebook (www.facebook.com/graciestaplesajc/) and Twitter (@GStaples_AJC) or email her at gstaples@ajc.com.