LOS ANGELES (AP) -- Seth Rogen let out a loud laugh when asked what he had done with Kim Jong Un, the North Korean leader who suddenly and inexplicably dropped out of sight about six weeks ago.
"It's all a marketing ploy," joked Rogen, whose upcoming comedy "The Interview" mercilessly mocks the rotund ruler. "We've hid him somewhere, and he'll be released one week before the movie."
Kim's absence is at least a bit easier to laugh about now that he has finally resurfaced, appearing in images released by state media this week.
But that time off the grid remains a mystery, and a looming Hollywood conspiracy theory certainly can't hurt "The Interview," in which Rogen and co-star James Franco portray celebrity journalists who've been ordered by the CIA to assassinate Kim.
"It is amazing," commented Rogen, who also co-directed the film, opening Dec. 25. "It's almost as if we gave (Kim) a list of, `Here's what you can do that would help promote our film.' And he's doing pretty much all of it."
The Emmy- and Golden Globe-nominated Rogen is best known for funny business, thanks to comedy blockbusters like "Knocked Up" and "Pineapple Express." And at present, the 32-year-old writer-actor-director is coming off his highest-grossing film to date, last spring's "Neighbors," with Zac Efron.
Monday, however, Rogen was talking serious business: Alzheimer's, the most common form of dementia. The disease has been a significant part of Rogen's life since 2004, when he began dating his wife, actress Lauren Miller. Her 63-year-old mother, Adele, has battled Alzheimer's for nearly a decade.
In a joint interview with Miller, Rogen said the biggest initial eye-opener was "there was literally nothing to be done about it."
"She was just in the emergency room last night," Miller said of her mother. "She doesn't walk. She doesn't talk. She can't dress herself. She can't go to the bathroom by herself."
The Rogens provide Adele with 24-hour care, which they acknowledge is beyond the financial resources of most Alzheimer's families. But they're also quick to point out the one tie that still binds everyone affected by the disease: There's no cure.
"We look to the government and we realize that it's ridiculously underfunded," the actor noted. So the Rogens are channeling their frustration into action. Friday marks their third Hilarity for Charity (HFC) variety show, where comics Sarah Silverman and Craig Robinson, Rogen's "50/50" co-star Joseph Gordon-Levitt and others will help raise funds for Alzheimer's support and research.
The Rogens said the happiest endgame would be for Alzheimer's and Hilarity for Charity to become things of the past, and for the two of them just to get back to their day jobs.
Miller, 31, is a full-time working actress and writer ("For a Good Time, Call..."), and Rogen has dropped hints about another project with Franco, teasing recently with two Instagram photos of the actors in the buff.
"I don't want to ruin it yet," Rogen said. "But we may have filmed something with the Discovery Channel involving `Naked and Afraid.'"
"And we might be naked and afraid in North Korea," Rogen said, with a laugh.