For the last three years, viewers have watched the Gosselin children grow up on Jon & Kate Plus 8 on TLC. Cameras rolled as they went on vacation, as they ripped opened Christmas presents, as they got ready for bed.

But as the children returned to television this week in a new series Kate Plus 8, the use of children like the Gosselins in reality TV shows is coming under greater scrutiny from lawmakers and mental health experts.

Psychiatrists and child advocates say the shows can invade a child's privacy and confuse a child's sense of identity. Reflecting that concern, a state lawmaker introduced a bill last week to strengthen child labor laws in Pennsylvania.

"Kids in these kinds of shows are not having a childhood, and you don't have to be a scientist to know what's going to happen to some of them as they get older," says Michael Brody, a Silver Spring, Md., psychiatrist and chairman of the Television and Media Committee of the American Academy of Child and Adolescent Psychiatry. "It can be a real disaster for them."

Kate Plus 8 is one of the more widely anticipated series premieres of the summer. But the new production featuring Kate Gosselin as a single mother raising eight children following her divorce from her husband, Jon, is hardly the only one featuring real-life kids in leading roles.

Toddlers & Tiaras, which tracks families with children in beauty pageants, started a new season last week on TLC, while Raising Sextuplets, featuring a couple with a half-dozen 2-year-olds, returns for its sophomore year June 24 on WeTV. Meanwhile, Wife Swap, which featured the "Balloon Boy" Heene family in its 100th episode, continues on ABC.

"This problem is much bigger than two shows about the Gosselins," says Brody, who used the term "child abuse" to describe two of the most notorious, now-canceled examples of the genre, CBS's Kid Nation - which put adolescents in a Lord of the Flies-style scenario - and NBC's The Baby Borrowers, which left infants in the care of untrained teens.

"That's why I'm so glad to see the state of Pennsylvania at least trying to do something to protect children who are in these shows now."

Pennsylvania State Rep. Thomas Murt (R., Montgomery) the sponsor of the bill, says he got involved in the issue after seeing a documentary on former child stars. In April after receiving complaints from constituents about the filming of Jon & Kate Plus 8, Murt held hearings on Pennsylvania's child labor laws to gauge how well they protect young performers.

"The hearing revealed some very, very serious concerns about this issue," Murt says. "We discovered there were really no on-set advocates for child entertainers in Pennsylvania."

Beyond issues of privacy and boundaries, reality TV is seen as being potentially dangerous to young child performers because of the very way it manipulates their own realities.

"Just doing retakes, where they stage a scene and then reshoot it again because something went wrong, really screws up a kid's sense of reality," Brody says.

Murt says members of his committee were told of a staged scene in which the Gosselin children were told it was Christmas so that the producers could get film of "the children coming downstairs in their pajamas, opening presents."

"And then they were told later on, well, no, it's not really Christmas."

"You can't behave normally with cameras and sound systems all around you," says Paul Peterson, who played Donna Reed's son, Jeff, in the popular 1960s family comedy The Donna Reed Show on ABC. Peterson now runs the California-based foundation A Minor Consideration, founded to provide support for current and former child performers.

"Cameras alter behavior. Just think back to what you felt like when your dad pulled out the Super 8 [home movie camera]. . . . Or imagine being an adolescent and just trying to fit in and then being confronted with an image of your potty training. You don't control those images."

Peterson says the "core issue is consent." As he sees it, "Children do not have the power to disobey - nor do they understand the full consequences of their participation."

In some cases, the consequences can shape the rest of their lives, a fact that was highlighted by the obituary of child sitcom star Gary Coleman, who died May 28 at 42. Coleman had said he tried twice to take his life with an overdose of sleeping pills.

Representatives of TLC, the cable channel most involved in showing reality TV programs featuring children, declined to be interviewed. But in an interview last year, TLC president Eileen O'Neill stressed the "opportunities" that being in the show offered the Gosselins - chances to travel and experience new adventures.

Annabelle McDonald, executive producer of WeTV's Raising Sextuplets, says the most important factor for her is that Bryan and Jenny Masche, parents of the six children, are in control.

"I am always checking in with them asking if everything is going OK," McDonald says. "They have to be comfortable with everything - comfortable with us being there, comfortable with the people on the set."

McDonald says she and the crew try to be "supersensitive to the needs of the kids," shooting only one five-day week out of a month.

Child psychiatrist Jenna Saul-Kuntz says that any examination of childhood and the potential effects of media documentation of it should start with the Dionne quintuplets, five identical girls born in rural Canada in 1934.

"We have to take a look at what happened to those quintuplets, because I think it more accurately reflects what's going on with these reality TV shows than what would be reflected even by child stars [in scripted series]," Saul-Kuntz says. "I say that because I think acting in a fake setting as a child star on TV is different from being in a reality TV setting where the cameras are always running" in the real setting of their lives.

Shortly after their birth in the pre-TV era, the Dionne girls were put on public display at a nursery, were photographed endlessly, and became the models for best-selling dolls. Ultimately, they came to believe that the experience ruined their lives.

"Multiple births should not be confused with entertainment, nor should they be an opportunity to sell products," the three surviving Dionne sisters wrote in an open letter published in 1997 in Time magazine. "We sincerely hope a lesson will be learned from examining how our lives were forever altered by our childhood experience."

Murt believes we can learn from such examples, and can do better by the kids of reality TV.

"Reality TV is not 100 percent reality, let's face it," he says. "The producers know what kind of show they want to film, and they create it. And you know what? That's not against the law. But my concern as a policymaker is to make sure that the kids who participate are protected. . . . If we can get that, it's a start."