Reagan appeared in "The Reporter," a Season 5 episode of the series about two young African American brothers from Harlem taken in by a rich white widower.
In the installment, which aired on March 19, 1983, younger brother Arnold (Gary Coleman) plays investigative journalist to verify rumors that drugs were being sold at his elementary school.
After meeting with one of the peddlers, who has plenty of "uppers, downers and goofballs" to go around, Arnold passes the claims onto the local newspaper.
First Lady Reagan happens to be in New York the day that information makes the paper. She goes to Arnold's home to get more details, and decides to drop in on the school to warn the students about the dangers of drugs.
The guest-starring role was just one of the ways the first lady attempted to fight drug abuse via her “Just Say No” campaign, aimed at the nation’s youth. In addition to "Diff'rent Strokes,' she appeared on several talk shows and traveled to schools around the country.
Her mission sparked a grass-roots movement, with more than 5,000 “Just Say No” clubs launched in the United States and abroad. In addition to collaborating with the Girl Scouts and Kiwanis Club International, Reagan hosted two international conferences on the problem, including one at the United Nations in 1985.
Get your life! Follow me on Twitter: @TrevellAnderson.