Downey's Downfall

If anyone ever had good reason to say no to drugs, it was surely Robert Downey Jr. The actor, 35, had already seen a promising career held back by substance abuse. He had been separated from his wife and son and lost his freedom--twice. But since his release from prison last August, Downey seemed to be turning his life around. He was in the middle of a ratings-boosting guest run as Calista Flockhart's romantic interest on Ally McBeal. He was set to star in a film with Julia Roberts and Billy Crystal and to take a turn onstage in Mel Gibson's production of Hamlet. He had proclaimed in one interview after another that he was ready to put drugs behind him.

Not ready enough, evidently. On Nov. 25, Downey was arrested at a luxury resort in Palm Springs, Calif., charged with possession of cocaine and speed and with violating the terms of his August parole. Against all logic and common sense, he had played with the same fire that had repeatedly burned him in the past--and this time his career could be put on hold indefinitely.

Yet crazy as Downey's latest bout of self-destructive behavior seemed, it was pretty typical for someone who is addicted to drugs or alcohol. Experts and addicts alike have long understood that willpower alone is helpless in the face of addiction, and in recent years science has started to figure out why. "The brain of a drug user," explains Dr. Alan Leshner, director of the National Institute on Drug Abuse, "is physically altered in ways that make it difficult to resist further use."

For public figures like Downey, the danger is especially great. "When you're famous," says Niki Moyer, a psychologist and clinical specialist at the Hazelden Foundation in Center City, Minn., "people respond to your public image, not to you as an individual. But direct human connection is an important key to healthy recovery." Going public with declarations that you're on the wagon, as Downey did in Vanity Fair and other publications, doesn't help. The feeling that your struggle is on full public view adds stress that can help trigger a relapse. That's one reason, says Moyer, that the Alcoholics Anonymous 12-step program and others like it counsel against self-disclosure to the media.

But ultimately, addiction is a physical disease of the brain caused by exposure to drugs. It starts, many neuroscientists believe, when alcohol, cocaine, amphetamines or other drugs boost the activity of a brain chemical called dopamine, which generates the sensation of pleasure. Flip the pleasure switch often enough, and nerve cells in many parts of the brain--especially in a tiny region known as the nucleus accumbens--become accustomed to the rush. When the switch is left in the off position too long, nerve cells feel deprived, a sensation the addict experiences as a nearly irresistible craving.

That craving can be staved off by substitute drugs--methadone for heroin, for example. But while doctors have found substitutes for nicotine and alcohol, there's nothing yet for cocaine and amphetamines. The craving can also be diverted through behavior-modification therapy and by regular participation in self-help groups like Narcotics Anonymous.

But even when an addict has been clean for a long time, says Leshner, the addictive brain has been permanently primed for relapse. One common trigger for returning to drugs is stress, which can send the recovering addict back to a proven stress reliever. Another is contact with people, places and things associated with drugs--cues that bring up dormant memory circuits laid down during active addiction and thus reawaken craving.

Since addiction is caused by drug exposure, Leshner believes, anyone who takes drugs long enough will become an addict. But "long enough" can vary dramatically from one person to the next. In Downey's case, it can't have helped that when he was six, he was given a joint by his filmmaker father (Downey Sr. has since expressed regret for that action). But without an understanding of individual biological differences, which scientists have yet to unravel, nobody can say whether those experiences turned Downey into an addict right from the start or whether repeated drug use over many years finally etched the circuits of self-destruction into his brain.

The good news, say experts, is that recovery is still possible after multiple relapses, although whether or not serving jail time has a beneficial effect is hotly contested. "Addiction," says Leshner, "is a chronic illness, just like high blood pressure. We can't cure it, but we're getting better at managing it all the time." So while Downey's situation looks very bad at the moment and for the immediate future, it may not be entirely hopeless.