Let's say you're serving time for possession of heroin, cocaine and an unlicensed .357 Magnum. Perhaps you messed up your chances of getting away with it because, a mere three weeks after the event, you went out on a bender and were found unconscious in a neighbour's child's bedroom. Now, there aren't strong guidelines for these matters but there are generally right things and wrong things to say when your case comes up for parole. For example, "I'm sorry", is a start. "It won't happen again", is better. "I'm sorry, it won't happen again - I just happen to think drugs are totally brilliant", is perhaps more information than the judge should hear.
Imagine how Robert Downey Jr's defence lawyer felt last year, then, when his client poured his heart out to the court. "It's like I have a shotgun in my mouth," he revealed, "and I've got my finger on the trigger, and I like the taste of gun metal." The presiding judge promptly jailed him for refusing to stick to the drug-testing programme imposed on him as part of his sentence for possession offences dating back to 1996.
Last month, however, Downey struck lucky. Lawyer Robert Waters totted up the amount of time Downey had spent in various institutions and concluded that his client should have been paroled last November.
And just a week, after he walked through the gates at Corcoran prison, it was announced that Downey would be joining the cast of Ally McBeal, making an eight-week residency as a potential suitor for the series' heroine. "We couldn't be more thrilled," the producers said. "We've admired his work and can't wait for the sparks to fly when he starts work." Famous last words? After all, as a result of his convictions, Downey is now an insurance liability, and part of his working regime for the last three years has included daily urine samples to prove that he isn't using drugs.
In doing so, Downey follows in the footsteps of fellow unreconstructed party animal Charlie Sheen, once a major consumer of cocaine and hookers, who confirmed his rehabilitation with a stint on the acclaimed political satire Spin City.
BUT is TV really such a safe place for recovering addicts? What about 300lb Saturday Night Live comedian Chris Farley, who died aged 33 two years ago after a cocktail of morphine, cocaine and another cocaine by-product reacted badly with his long-suffering heart? And what about former Airwolf star Jan-Michael Vincent, who broke his neck, dislodged a retina and seriously damaged his vocal cords back in 1996 when his car crashed in an alcohol-related incident? And what about David Strickland, the 29-yearold co-star of Suddenly Susan, found hanging in a Las Vegas motel room last year after skipping a court hearing for drugs charges and spending the night in a lap-dancing club? TV might seem like an ad hoc Betty Ford clinic, but actors are advised that Cathode-Ray Babylon is no picnic. Ask Matthew Perry, whose pain-killer addiction, combined with a weight problem, recently made him the object of intense tabloid scrutiny.
By far the most notorious example of TV crash-and-burn has to be the apparently innocuous integration comedy Diff'rent Strokes (1978-84), in which a benign millionaire adopted two cute black kids and brought them to live in his wealthy Manhattan apartment. Some 20 years later, its three teenage stars are now dead, in rehab or broke. Dana Plato, who played Kimberly, hit the skids when the show was axed, developing a drink problem, then a pain-killer addiction. She was arrested first in 1991 for robbing a video store and again the following year for forging a prescription for Valium, but seemed to be on the mend. After a harsh tongue-lashing from listeners during an appearance on the Howard Stern show last year, however, Plato took a fatal overdose of painkillers; she was 34.
Todd Bridges, who played Willis, fared better. In 1989, he was arrested on suspicion of shooting a drug dealer in a crack house. At the time Bridges was said to be in the grip of a 14-gramme-a-day habit. He was acquitted, but the 35-year-old now claims to have been clean for seven years. And finally, there's Gary Coleman, the diminutive Arnold, whose liver problems stunted his growth and who sued his parents for misappropriation of the money he made during the series - said to be $70,000 per episode. Now 32, Coleman filed for bankruptcy in August last year.
Robert Downey Jr turned 35 this year, and it remains to be seen how firm his resolve is. But he has plans: after Ally McBeal he is to turn to the LA stage in Hamlet, directed by Mel Gibson. TV may seem like a healthy crutch, but will the goldfish-bowl life that comes with Ally McBeal simply make things more unbearable if the taste of gun metal once again whets his appetite? And isn't he just setting himself up as another circus sideshow to sate the public's morbid curiosity? As he said himself recently, "You know, there's nothing worse than a reformed anything."
The new series of Ally McBeal, with Robert Downey Jr, will start on RTE in January. The current series is still showing on Channel 4 on Wednesdays at 10 p.m.