It wasn’t the kind of connection that you might expect to happen backstage at a rock concert.

But a chance meeting between the nation’s top doctor and a popular actress last year has led to a new warning about the dangers of addiction.

It all started behind the scenes at the “Unite to Face Addiction” concert on the Mall, a show featuring the likes of Sheryl Crow and Steven Tyler. Actress Allison Janney and U.S. Surgeon General Vivek Murthy were among the speakers, and the two got to chatting (we’re imagining Crow’s “All I Wanna Do” was playing in the background).

Janney issued one of those polite/sincere “if you’re ever in California …” invites to drop by the set of her show, the CBS sitcom “Mom.”

Well, the doc took the former “West Wing”-er up on the offer, and the result was a PSA featuring Janney, Murthy and “Mom” co-star Anna Farris, which will air on the show’s Feb. 18 episode.

It’s an apt tie-in, since Janney and Farris play a mother-daughter duo both in recovery from alcoholism and drug abuse. Fortunately, Murthy’s comedic timing wasn’t tested in the 30-second spot. “Drug overdoses kill more Americans than car crashes,” he says.

Watch the video here.