By Colleen Kane, CNBC.com
The Hollywood machine loves a fresh-faced, button-nosed, apple-cheeked, sassy child performer. Once that precocious kid dares to grow up, however, the system is not kind.
The unfortunate trend is that for every well-adjusted former child star, there are two troubled Coreys. Behind them is a staggering rogues gallery of has-beens such as Lindsay Lohan, Dustin Diamond, and so on, with each of them doing one or more of the following: falling down drunk, overdosing on drugs, crashing a car, committing a crime and/or making a porno. Or they end up stuck in a purgatory of appearing in one reality TV show after another. At worst, their demons lead them to an early demise.
Happily, however, some child stars, such as Natalie Portman, Anna Paquin, and Leonardo DiCaprio, do transition smoothly into acclaimed adult acting careers. Others venture into different fields altogether.
We assembled a list of child stars that have moved on from acting (for the most part) to achieve success in other fields-a handful still in the entertainment world. Click ahead to see where they are now.
Best known as: The kookily clad individualist Blossom in the 1990s TV sitcom of the same name.
What she's been up to since then: Oh, not too much. She only earned a PhD in neuroscience from UCLA after turning down Harvard and Yale universities. Now 35, Bialik is a mom, and, while not a neuroscientist, she plays one on TV.
You can still catch her in: "The Big Bang Theory" and the upcoming movie release "The Chicago 8."
Mary-Kate and Ashley Olsen
Best known as: The Olsen twins rose to fame as infants, when they took turns playing little Michelle Tanner in the squeaky-clean 1990s TV family sitcom "Full House."
What they've been up to since then: Now 25, these two are pint-sized moguls. After "Full House," the pair became a brand that extended to albums, videos, books, movies, and a fashion line. In 2009, CBS put their escalating net worth at an estimated $40 million each.
You can still catch them in: They don't really need to work ever again, but Mary-Kate has remained (slightly) more active in the entertainment industry than Ashley, with about one project a year-this year's was the role of Kendra in the fairy tale update "Beastly."
Best known as: Kevin Arnold, young, all-American protagonist in the 1990s TV paean to 1970s childhood, "The Wonder Years."
What he's been up to since then: Now 35, Savage has directed the great TV comedies "It's Always Sunny in Philadelphia" and "Party Down," as well as episodes of "Franklin & Bash," "Modern Family," and many more.
You can still catch him in: The TV movie "Being Bin Laden" and voiceovers on the animated TV series "Generator Rex."
Best known as: Winnie Cooper, Kevin Arnold's prim temptress on the TV show "The Wonder Years."
What she's been up to since then: McKellar majored in math at the University of California, Los Angeles (UCLA) , and she co-authored a paper on mathematical theorem. Now 36, she is the author of three best-selling books: "Math Doesn't Suck," "Kiss My Math," and "Hot X: Algebra Exposed," which encourage girls of different grade levels to get involved with math.
You can still catch her in: The in-production film "Mancation," the animated series "Young Justice," and, like former co-star Savage, she provides voiceovers on the animated series "Generator Rex."
Soliel Moon Frye
Best known as: The adorable ragamuffin Punky Brewster in the 1980s TV sitcom of the same name.
What she's been up to since then: At age 35, Frye is a self-styled "momtrepreneur"-she just released her parenting memoir "Happy Chaos," she's Target's Mommy Ambassador, and she has nearly 1.5 million followers on Twitter.
You can still catch her in: Frye voiced a character in the pilot and a few other episodes of the Jimmy Neutron spinoff cartoon, "Planet Sheen."
Best known as: In the 1960s, he became famous as the pint-sized redhead Opie Taylor from TV's "The Andy Griffith Show," and in the next decade he played Richie Cunningham in the TV sitcom "Happy Days."
What he's been up to since then: Now 64, he's an accomplished director and producer, with recent producing titles including "Cowboys & Aliens," "Restless," and "The Dilemma." Recent directing credits for upcoming films include "Under the Banner of Heaven" and "Rush."
You can still catch him in: The voiceover narration of the promised "Arrested Development" movie. (Here's hoping!)
Click here to see more Child Star Successes
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By Colleen Kane, CNBC.com