From the title alone, you'd expect "Please Don't Hit Me, Mom" to be at least a two-hankie heart-ripper. Add the titillating lure of Patty Duke Astin as an abusive mother and her own 8-year-old son, Sean, as the battered child, and you're ready for a TV takeoff of "Mommie Dearest."

But half a Kleenex should suffice viewers of this premiere presentation of the "ABC Theater for Young Americans" tomorrow night at 7 on Channel 7. Although a bit too pat and contrived to fulfil its tear-jerking promise, it is still a compelling hour of prime-time pathos likely to please a young audience.

The story revolves around Brian Reynolds, a quiet, withdrawn child who has moved to a new town along with his mother and older brother. His parents have recently divorced, and his mother takes out her varied frustrations -- loneliness, a first job, a weight problem -- by slamming him around.

Brian's older brother Michael, a tall, good-looking high school basketball star, pretends the problem doesn't exist. But a cute reporter on the school newspaper develops a crush on Michael, begins baby-sitting for Brian and figures out what is going on.

She has learned, through a convenient class field trip to the hospital, that "there are more than a million reports of child abuse per year, and once every four hours one of those kids dies from being battered." Parents who abuse children "are the kind of people who get swamped with pressures they can't handle. They are sick people who need help." Her dilemma in reporting the problem provides one of the show's best scenes.

Sean Astin makes a fine television debut as Brian. From the opening scene -- in which a tough and tight-lipped Patty Duke Astin roughs him up for an accident that was not his fault -- he uses a set of sweet blue eyes and a painful smile to give a touching performance.

As his mother, Astin is less convincing. It is difficult to tell whether it's the stilted dialogue or the task of abusing her own son that keeps her from being totally believable. At one point -- when Brian gives her a drawing he's made -- she flips from harsh to happy like a robot whose button has been pushed.

Yet some moments work beautifully. When Astin breaks down and admits she needs help and the son she's abused moves in to comfort her, even the toughest cookie is bound to crumble.