A huge happiness gap is opening between American adults and teens.

The big picture: Depression has hit teens much harder than adults in the smartphone era (charted above), according to National Survey on Drug Use and Health data.

Zoom in: The massive gap is clear in the most recent World Happiness Report.

By the numbers: In the oldest age group, America was the world's 10th happiest country.

• Among the young, America fell to 62nd place.

Between the lines: Young people in North America are now less likely to say they're happy than older populations.

• That's a massive reversal from most regions, where younger people tend to be happier.

Go deeper: The loneliest generation: Inside the Gen Z mental health crisis