(Axios) – Preteens who own smartphones are likelier to have depression, obesity and insufficient sleep than their peers, according to a new University of Pennsylvania-led study.

Why it matters: Roughly half of American kids now own a smartphone by the time they turn 11.

Pediatric health groups have recommended appropriate screen time for youths, but there are no public health guidelines on the appropriate age for kids to first get a smartphone, the study says. (Read More)