Seventeen-year-old Randy opened up to Nancy Reagan, telling the first lady things about his life that he had just recently come to realize.

"I've tried my best to learn what drugs and alcohol can do to you, but I know now that you've got to ask for help," said the Mechanicsville youth.

Randy was among students who met Mrs. Reagan yesterday as she toured Edgemeade, a school and residential treatment center in Upper Marlboro for emotionally disturbed teen-age boys.

During her tour of the southern Prince George's County school, the first lady complimented Edgemeade for its use of "foster grandparents" as counselors for troubled youths and again spoke out against drug use, two of her favorite themes.

"Each of you has a dream, and I'm not talking about the new stereo or new tapes," Mrs. Reagan told the students.

"I'm talking about recognizing that you are not alone and . . . realizing that your dreams don't stand a chance against drugs."

The first lady also urged the students to talk with their elders about their dreams.

"I hope you will talk with your foster grandparents because they want to listen to you and help you," she said.

The first lady was the second White House emissary to visit Prince George's County in two days. On Wednesday, President Reagan was at Suitland High School to announce additional funding for special magnet schools.

White House officials said Mrs. Reagan's visit was arranged by ACTION, a federal government agency that administers the Foster Grandparent Program.

The school, with 56 students ranging in age from 12 to 19, is part of Edgemeade. Founded 27 years ago, it has a nonprofit, residential treatment facility for adolescent boys with severe behavior, personality or neurological disorders.

The school concentrates on the individual academic needs of students, who are referred there by social service agencies, by educating them at their own pace rather than in the traditional public school grade levels.

Abby Crowley, principal of Edgemeade, said the first lady's visit could improve the morale of some students whose low self-esteem had led them to drugs and alcohol.

Shirley Lazowicki, a drug education teacher at the school, said the discussion with Mrs. Reagan was similar to how teachers conduct their classes.

"They were a little nervous about talking with her at first, but I think they understood what she was saying, and for some of the kids it will help," Lazowicki said.

Catherine Diggs, 74, a foster grandparent at the school for nine years, told Mrs. Reagan that she enjoys working with the Edgemeade students.

"I just like getting up in the morning and getting out of the house," Diggs said. "I don't mind dealing with their problems."

Mrs. Reagan spent a little less than two hours at the school, visiting a building trades class, a gym class and the drug education class. Students presented her with a homemade kitchen cutting board and a plaque.

James P. McComb, executive director of the Edgemeade treatment facility, later said Mrs. Reagan was the most prestigious visitor in the school's history.

"The kids really took what she said to heart, and I think they are going to remember this for a long time to come," he said.

EDGEMEADE

Edgemeade has two primary programs, a residential treatment center and a school. It is a private institution that receives some state grants for construction. Most of its $2 million annual operating budget comes from private donations, corporate contributions, loans and fund-raisers. The treatment center serves 48 boys, ages 12 through 19, who have severe behavior, personality and neurological disorders.

The school has 56 residential and day students at various grade levels who work at their own pace. Fourteen foster grandparents work with the students in school daily.