"I can handle it," says the 15-year-old drug addict, but this phrase falls neatly into the category of Famous Last Words, contemporary edition. "Not My Kid," the CBS movie at 9 tonight on Channel 9, compellingly dramatizes the fact that drug abuse can become a tragedy even in seemingly normal, otherwise untroubled middle-class households. The film, and the point, are well made.

One of those problem dramas more interesting for its utilitarian value -- spreading information about the risks of abuse and the avenues available for the parents of adolescent abusers -- than its cinematic qualities, the movie nevertheless maintains a high level of credibility. As the young druggie, Viveka Davis shapes a battery of symptoms into a dimensional character.

The parents are played by Stockard Channing, zoning down into a less frantic role than her usual wacky turn, and George Segal as the doctor father. Segal recently joined the long list of celebrities to admit to having developed a drug dependency problem. All the performances are not only capable but conscientiously synchronized with the bluntly informational tone of the film. It is a kind of secular evangelism whose message seems well above being quibbled with.

Having their wits about them once the initial period of accusation and recrimination are over, the parents enroll their daughter in a group treatment program that is almost Moonian in its severity and regimentation. The young woman eventually finds the courage to stand and testify in front of parents and peers that she indeed has developed a crippling addiction. The scenes of other youngsters recalling their drug histories are effective, but one is aware that these are performances by actors, not as moving as footage of actual students in real rehabilitation centers, the kind shown on George Schlatter's recent "S.O.S." special and on other programs.

Drug abuse is one of those topics on which a good deal of preachiness must be tolerated. "Not My Kid" makes the sermonizing bearable and commendable. The film was written by Christopher Knopf and directed by Michael Tuchner. Mark Snow's music has to carry certain scenes almost by itself, and it does, strikingly. The definitive TV film on this subject may remain the more harrowing, and less hopeful, "The Death of Richie," which starred Robby Benson and aired on NBC in 1977, but "Not My Kid" is an important addition to a somber literature.

Following the film, Nancy Reagan will appear in a pretaped sequence to recommend books on drug abuse among the young as part of the CBS/Library of Congress "Read All About It" program. Among the books Mrs. Reagan will recommend is "Not My Kid," by Miller Newton and Beth Polson. Polson, who produces the excellent Barbara Walters celebrity specials for ABC, was the executive producer and guiding force behind this movie. She has referred to it as a "love project." That comes through. 'The Golden Years of Television'

Where are the men from Texaco? Dispersed from Maine to Mexico? There's Uncle Miltie, but he isn't wearing a woman's dress, nor so much as a woman's hat, and he appears as unhappy as a soggy-winged Icarus. This week's installment of "The Golden Years of Television," at 10 tonight on the Maryland Public Television stations, is Milton Berle's seventh season opener as an NBC TV variety star. The 1955 show makes rather magnificent historical viewing, more melancholy now than uproarious.

Berle exploded onto the scene in 1948, not long after the atomic bomb, with "The Texaco Star Theater," a Tuesday night national ritual that began to fade in about four years, as the TV set population boomed and other alternatives became available. Berle decided to mellow out his act and put himself in the care of the civilizing Goodman Ace, veteran TV writer. Unfortunately, a tasteful Berle is a dull Berle. With guest star Mickey Rooney blowing lines and stumbling over himself, Berle began his seventh season shakily.

But there are innumerable aspects to the production that are fascinating in retrospect. The plot of the show (plots were added as part of the revamping) has Berle faking a broken leg to get publicity for himself. The reference is to an incident in which Jackie Gleason slipped on dry ice and broke a leg at the end of one of his shows on CBS. "Naw, they wouldn't can me," Berle jokes of his sponsor, Buick, but at the end of the season, Buick did drop Berle. And picked up Gleason.

As for Rooney, he later played a merciless TV comic patterned partly on Berle for the savage "Playhouse 90" drama "The Comedian." Others appearing on this Berle show include columnist Dorothy Kilgallen and "regulars" like Arnold Stang ("oooh, chip chip chip!" he would say) and, as Berle describes her, "our new little star, Nancy Walker." The credited writers include Selma Diamond and the choreography was by Herbert Ross, later a prolific movie director.

Alas, the packagers of this "Golden Years" anthology, Avery Productions, crudely butchered the programs for sales to commercial stations. As much as 10 minutes have been removed, and sketches are interrupted almost in mid-joke. Although there are no commercials on this public TV airing, the interruptions -- visual bumpers and musical "stingers" -- abrasively remain. Mendacity! And unforgivable, except that the chance to see even a bowdlerized Berle, on film and yet still somehow magically "live," is something to be grateful for. This glimpse of the downside of an era isn't much less than priceless.