LOS ANGELES (Reuters) - Sometimes all it takes to solve a puzzle is a different way of looking at it.

Former "Will & Grace" actor Eric McCormack is hoping audiences will do just that when he returns to television next week, not as a witty gay lawyer but as an eccentric professor with paranoid schizophrenia.

"Perception", which debuts on July 9 (Monday) on the TNT network, sees McCormack playing lovable neuroscientist Dr. Daniel Pierce, who is recruited by the FBI to use his brilliant but delusional mind to help solve complex crimes.

McCormack describes Pierce and the new show as "'A Beautiful Mind' meets 'Columbo'" - a combination of the Oscar-winning movie about a mathematician and the TV detective series. Others have likened "Perception" to medical TV drama "House" for crime show enthusiasts.

Arrogant, outspoken and largely closed-off from other people, Pierce is a character who despite having a real job as a university professor can't help solving mysteries, whether it is a crossword puzzle or an unsolved crime.

Proud as he is of "Will & Grace" - a TV sitcom about a gay man and straight woman who are best friends - and its role in re-shaping the US cultural landscape in terms of gay acceptance, McCormack says that six years after the it ended, he is hoping audiences will accept him in a new light.

"Actors are supposed to show versatility, but you are saying to audiences 'you have lived with that guy on screen for eight years, and now I want you to live with this new guy.'"

"I can't expect everyone to go along with it, but I hope people will give it a try and see there is fun in the same actor creating something totally different," McCormack told Reuters.

"Perception" is as much about the character of Pierce and his attempt to keep his paranoid schizophrenia at bay without medication as it is about the crimes he solves with FBI agent and former student Kate Moretti, played by Rachael Leigh Cook.

BATTLING SCHIZOPHRENIA

McCormack said he did weeks of research into the mental illness and how it manifests itself. He read about Nobel economics laureate John Nash, whose story was told in "A Beautiful Mind," and devoured University of Southern California law professor Elyn Saks' account of her own struggle with schizophrenia in her 2007 book "The Center Cannot Hold."

"I don't think there is a single show where on some level my character's condition doesn't escalate. The real thrust of the first 10 episodes of 'Perception' is that, because I am not on my meds, the more cases I take on, it is a little clearer that it is ungluing my way of life. But there will always be some crime to solve too," McCormack said.

McCormack started his career playing classical and Shakespearean roles before becoming a household name in his Emmy-winning turn as neurotic Will Truman on "Will & Grace."

Since the series ended in 2006, the 49-year-old actor has struggled to find his feet. TV advertising drama "Trust Me" was canceled after one season in 2009 despite good reviews, and his sci-fi movie "Alien Trespass" was a box-office flop.

McCormack fared better as con artist Clark Rockefeller in 2010 TV movie "Who is Clark Rockefeller?" and he is currently playing what a jerk in the Broadway play "The Best Man." He also appears in the independently made political satire film "Knife Fight," which premiered at the Tribeca film festival in April.

"I have to show the world there is another side of me. I have to probably not go and play a whole bunch of other gay roles," said McCormack, who is straight in real life.

"But I am prouder now of 'Will & Grace' than I have ever been. There a lot of guys who write me letters saying I don't know how I would have come out to my parents without that show.

"We were never political about it at the time ... but I think what we did little by little, by having middle America watch the show, was as valuable as all the speeches and rhetoric and parades in the world."