DiCaprio discusses the ‘Inception’ of his new role

Drug addiction. Child abuse. The politics of the diamond trade. Institutional corruption. Post-traumatic stress syndrome.

From early movies like “The Basketball Diaries” and “This Boy’s Life” to recent hits “Blood Diamond,” “The Departed” and “Shutter Island,” Leonard DiCaprio has tackled his share of weighty issues.

With a starring role in the sober sci-fi brain-teaser “Inception” arriving in theaters Friday, July 16 and an upcoming turn as the title G-Man in Clint Eastwood’s “Hoover” biopic, DiCaprio has no plans of lightening up anytime soon.

Why so serious, Leo?

“I don’t really question (the themes of movies) when I read a script,” says the actor, 35. “If I feel like I can be of service to a role, that it emotionally engages me, that it’s something that interests me, and the director is someone who has the capacity to pull off the ambitious nature of the screenplay, I never question it.

“So, yes, I guess that a lot of my films have been more serious in tone. That’s something I don’t try to deny. Look, I’m a very fortunate person. … I grew up in L.A., and a lot of my friends are actors and many of them don’t (have the luxury) to choose roles, so I realize every day how lucky I am. So while I’m here, I’m going to try and do exactly what I want to do.”

“Inception” and the chance to collaborate with “Dark Knight” director Christopher Nolan was at the top of DiCaprio’s to-do list.

“There are very few directors, I think, in this industry who would pitch to a studio a multilayered, almost at times existential high action, high-drama, surreal film like ‘Inception,’ but if you’re seen Chris’ past work in ‘Memento’ and ‘Insomnia,’ you know he’s able to portray these highly condensed, highly complicated plot structures and give them emotional weight.”

“Inception” is far from a conventional thriller. DiCaprio stars as Dom Cobb, a dream thief who penetrates people’s subconscious minds while they’re sleeping in hopes of stealing ideas. In the world of corporate espionage, Dom is a giant. But he’s growing weary of his assignments and is eager to return home to his beloved (Marion Cottilard).

For his last job, Dom agrees to attempt the near-impossible: an inception — or the implantation of an idea in the mind of a business executive (Cillian Murphy). Co-starring with DiCaprio are Ken Watanabe, Michael Caine, Joseph Gordon-Levitt, Ellen Page and Tom Hardy.

Budgeted at $160 million, “Inception” dreams big. The action shifts between real worlds and dream states, trotting around the globe to locations in Morocco, Tokyo, Paris, London and Calgary, Alberta.

DiCaprio bristles a bit when it’s suggested that, in some strange way, “Inception” and Martin Scorsese’s “Shutter Island” are bookends of mind-twisting suspense.

“Bookends? I don’t know,” he says. “Like I said before, I think these (movies have) characters and plot structures that I was compelled to do. I’m lucky to be able to do them. So I jump on those opportunities. Traditionally, I’ve always tried to work with the best directors that I can. These types of films which are psychologically dark at times, I find them extremely exciting to do because there’s always something to think about.

“There’s nothing more boring to me than showing up on set, saying a line and knowing that my character means exactly what he’s saying. It’s interesting to have an unreliable narrator in a film and that’s what both of these films have in common. That notion was extremely exciting for me.”

The idea for “Inception” took root 10 years ago in Nolan’s imagination. Following his success with “Memento,” the filmmaker was eager to continue exploring the outer limits of human consciousness.

“I’ve been fascinated by dreams my whole life, since I was a kid,” says Nolan. “I think the relationship between movies and dreams is something that’s always interested me. My primary interest in dreams is this notion that while you lay asleep, you create an entire world which you experience without realizing you’re experiencing it. I think that says a lot about the potential of the human mind, particularly the creative potential.”

While Nolan always envisioned the movie as a palm-sweatingly intense thrill ride, it took him a few dozen more re-writes to discover the story’s emotional core. “I sort of grew into the film in a sense,” he recalls.

A big fan of heist movies, Nolan appreciated the “almost deliberately superficial” nature of many beat-the-clock thrillers. But, he says, there’s nothing superficial about dreams and their ability to tap into people’s deepest desires.

“Heist movies tend not to have high emotional stakes,” says Nolan. “What I realized, over the years, is that when you’re talking about dreams, you have to have emotional consequences and resonances. So that was really my process over the (last decade), finding my relationship with the love story, the tragedy of it, and connecting with the story’s emotional side.”

Even though Nolan has made generous use of computer-generated-imagery in past films, he was hoping to tell the story of “Inception” without relying on too many special effects. For instance, rather than utilize a CGI blizzard, Nolan and company waited for a real snowstorm to blanket Calgary.

In London, the set of a long hotel corridor was constructed so it would rotate a full 360 degrees, allowing Nolan to create the effect of zero gravity. Members of the crew also masterminded a hotel bar set on a gigantic gimbal that enabled the entire room to tilt and then slowly right itself, creating a surreal, only-in-a-dream effect.

Before production began, DiCaprio read everything he could get his hands on about the science of dreams despite having little personal interest in the subject. “I’m not a big dreamer and never have been,” says the actor. “I only ever remember fragments of my dreams.”

After finishing up Sigmund Freud’s “The Interpretation of Dreams,” DiCaprio decided to forgo the experts in favor of Nolan, who had his own specific notions about what transpires in dreamland.

“I sat down with Chris for two months every other day and we talked about the structure of this dream world and the rules that apply in it,” says DiCaprio. “The only thing that I extracted from all the research I’d done into dreams was that there’s no specific science you can apply to dream psychology. I think it’s up to the individual.

“We suppress things, emotions and thoughts during the day that we obviously haven’t worked out. So, in our sleep, in our subconscious, we sort of randomly fire off different story structures in hopes of (resolving our problems). When we wake up, we should pay attention to our dreams.”

At the moment, DiCaprio is paying attention to “Hoover,” a biopic about the former director of the FBI which Clint Eastwood is preparing to direct later this year.

“J. Edgar Hoover is fascinating because he had his hand in some of the most scandalous events of American history,” notes the actor. “He was involved in everything from the Vietnam War to Dillinger to Martin Luther King and JFK.”

As for Hoover’s private life, which reportedly included dressing in drag and carrying on an affair with FBI associate director Clyde Tolson, DiCaprio says at least some of the more controversial incidents will be depicted.

“The movie’s about the secret life of J. Edgar Hoover,” DiCaprio notes. “Will I wear a dress? Not as of yet. We haven’t done those fittings so I think not.”

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