For every Jodie Foster or Elizabeth Taylor who made the transition from child star to even more successful adult star, there are plenty of others who faded into obscurity or worse.

Judy Garland, the subject of the new film Judy, is often cited as a prime victim of the dangers of the Hollywood studio system. Judy flashes back periodically to show her as a teenager at M-G-M being overworked, threatened and being given pills for weight loss, energy and sleep. This is obviously not conducive to a healthy life and some, like Garland, were less able to deal with the effects.

Kids having stage parents living vicariously - and making a living - through their children is one factor in child-star issues. Garland's mother was complicit in her daughter's ill-treatment. Being the main family breadwinner at a young age reverses family responsibilities and deprives the child actor of a normal childhood.

Sometimes the young performer doesn't even get to enjoy the fruits of his or her labours: Jackie Coogan (The Kid) earned millions but his mother and step-father squandered most of it, leading to a law setting aside a portion of a child actor's income in trust.

And some kids have been sexually assaulted. But Hollywood seems inclined to let even convicted abusers keep working regardless (like Victor Salva, who made Jeepers Creepers).

For children, losing stardom and its perks can be psychologically as well as economically devastating. Media attention to any problems or misdeeds can also be disproportionate.

Drew Barrymore (E.T.) is a child-star survivor. She developed a drinking problem at 11, at 12 was a drug addict, and attempted suicide and entered rehab at 13, but sorted things out to remain a force on and off screen.

Some actors did not keep their peak child-actor popularity but maintained respectable mid-tier careers, like Roddy McDowall (Lassie Come Home). Others got out of show business. Shirley Temple, one of the biggest of all child stars and another whose parents spent most of her earnings, became an ambassador and was chief of protocol of the US.

Some couldn't cope as their careers faltered. Bobby Driscoll, (Disney's Treasure Island) died at the age of 31 a penniless drug addict and was buried in an unmarked pauper's grave.

Drugs and alcohol are always a temptation and can be indulged and enabled as long as the star keeps working. River Phoenix (Stand By Me) died from an overdose in his 20s while still a big star, to the shock of many.

Macaulay Culkin (Home Alone) was the first child star to make $1 million for a film, and he took a break to attend high school (more formal education than many kids get). But there were family problems: his eventually estranged father-manager, a former child actor, was envious, Culkin says, of his son's success. As an adult Culkin had a drug arrest but he's returned to acting as well as music, albeit with less prominence.

The dangers of being a child performer are always present, as well as the possibilities, and must be weighed up by aspiring young actors. And their parents.