The New York medical examiner's office says it will take 10 to 14 days to get the results from an autopsy performed today on 28-year-old actor Heath Ledger, who was found dead yesterday in his Manhattan apartment. Until then, we can only speculate about whether the actor's untimely passing was an accident, a suicide attempt or, as some are suggesting, a drug overdose.

This much is clear, though: Emerging details about Mr. Ledger's recent life paint the picture of a deeply troubled and increasingly isolated individual. Perhaps this deteriorating mental state was entirely biological, although past interviews and new information coming out lead us to believe that the actor's intense portrayals of late took a toll on him. It would be ludicrous to suggest that acting killed Mr. Ledger, although it seems reasonable to ask whether the pressure he felt to perform and the places he went in order to give his best contributed to his demise.

In an interview published in the New York Times in November, Mr. Ledger said he "stressed out a little too much" while playing one of six Bob Dylans in Todd Haynes' "I'm Not There." When I spoke with the director that same month, he told us that Heath "was so hard on himself."

In that same New York Times interview, Mr. Ledger spoke about his upcoming role as the Joker in the "Batman Begins" sequel, "The Dark Knight." He described his character as a "psychopathic, mass-murdering, schizophrenic clown with zero empathy," then mentioned how he'd had trouble sleeping of late. His mind wouldn't stop racing, even when he took an Ambien, he said.

Not long before this, people had begun to notice a change in Mr. Ledger, observing that he'd grown reclusive, erratic and unkempt following his split with actress Michelle Williams (the mother of his 2-year-old daughter, Matilda) in September. It's entirely possible that Mr. Ledger's sleepless nights were related to the loss of this relationship, which, being a star, he did not get to mourn privately. Yet, his comments do leave one to wonder about the impact that going so deeply into such dark places on screen might have had.

One particularly dark place Mr. Ledger went in recent years was in "Candy," a 2006 film that had him playing a heroin addict. I spoke with the actor in November of that year, and in between yawns (he said he was tired), he told us how he and co-star Abbie Cornish had gone to a rehab clinic to prepare for the role, learning the proper techniques for shooting up and the way the drug might effect the body at various times. Those of who've seen the film know what an emotional ride "Candy" must have been for the star. On screen, Mr. Ledger realistically took us through every injection, every ache, every impulse of a drug addict.

When I asked if he drew from his own experiences, the actor said, "Not really. I can certainly understand addiction. I've been addicted to tobacco; I know what it is to crave something, to be thirsty. I've certainly smoked a joint, so I know what it's like to be high."

He made no mention of ever having shot up, but several reports now claim that prior to Mr. Ledger's death, he was battling a heroin addiction and other substance abuse problems. A source told London's Daily Mail that "he had a stint in rehab last year when he was treated for heroin."

Supposing Mr. Ledger had been addicted to heroin before "Candy," it's obvious why he wouldn't divulge that information in an interview. But if we take his words at face value, one could reasonably infer that this particular film may have introduced him to a destructive and potentially deadly behavior.

Much has been made about how watching sex and violence on TV and film may encourage such behaviors, and it would stand to reason that watching scenes about drug abuse might have a similar effect. Now just think about the compounding effect that not just seeing but actually emotionally inhabiting and recreating these scenes might have. Look at the life of River Phoenix, for example, a similarly intense actor whose role as a drug-using street hustler in 1991's "My Own Private Idaho" left some people wondering if it hadn't contributed to his eventual heroin and cocaine overdose two years later.

We'll find out in the coming days just how credible the reports about Mr. Ledger's drug abuse are, and we'll also find out more about the circumstances surrounding his death. But perhaps we shouldn't wait any longer to start thinking about this: Acting is a wonderful thing that brings joy to many and a life's work to others, but role research and preparation may — when taken to a literal-minded extreme — be hazardous to young stars' health. Maybe it throws them into a mental state they find it hard to get out of. Maybe it introduces them to a damaging new behavior. And maybe we should start listening for the warning signs — for those times when actors start to reveal just how sleepless their nights are becoming.

— Jenny Mayo, arts and entertainment writer, The Washington Times