Dementia is a problem of the elderly, right? Generally that's true. But there is one form of the disease that can strike people when they are very young, in their 20's or even their teens. It's called Frontotemporal Dementia, or FTD.

"We were seeing our son disappear before our eyes little bit by little bit."

Sue and Bill Bishop are watching a disease called Frontotemporal Dementia, or FTD, consume their son Brad. The brain disorder with no cure is changing him from a caring young man with a bright future into a person whose behavior is erratic, childlike and at times inappropriate.

"Who it it? Who is it? Who is it?"

"It’s not Brad. It's Brad's body. Of course even that is different."

Brad's first symptoms were subtle personality changes. He'd forget to return phone calls and emails. He'd act childlike in public. And he grew self-centered; a trait his parents say was completely out of character. And as the disease progress, symptoms got much worse.

Brad became agitated around people and he couldn't control the urge to eat.

"So literally we had to put locks around the fridge and freezer."

For more than a year doctors did not know shy this was happening.

"When we were told that there was something rapidly, aggressively attacking our son's brain and we don't know what it is, I lost it."

"Just going to check your reflexes."

Then the Bishops met Mayo Clinic Dr. Brad Boeve, an FTD specialist.

"That’s when we started our journey. A long painful journey, but at least we know what Brad has."

"For the family, it's frankly a nightmare."

Dr. Boeve says FTD affects the frontal and temporal lobes of the brain which control things like judgment, language and social behaviors. Research suggests that ftd is the result of malfunctioning proteins that cause your brain cells to die prematurely. This causes brain tissue to shrink.

"These are Brad's brain scans. You can see that over time this area of his brain has steadily been shrinking."

Medications help manage some symptoms of FTD, but at this point nothing can stop it.

"We want him to be safe. Comfortable."

And they want others to know about FTD. So families can intervene early and help their loved ones get the supportive care they need as they live with this devastating disease.

Even though there's no cure for FTD, Dr. Boeve says there is some hope. As researchers learn more about how it affects the brain, they will be able to tailor medications to hopefully slow the rate of progression, or even prevent it.