Early in “How to Break Up With Your Phone,” Price invites her readers to take the Smartphone Compulsion Test, developed by David Greenfield, a psychiatry professor at the University of Connecticut who also founded the Center for Internet and Technology Addiction.

Early this year, influential activist investors who hold Apple shares also called for the company to focus on how their devices impact kids.

In a letter to Apple, hedge fund Jana Partners and California State Teachers’ Retirement System (CalSTRS) wrote “social media sites and applications for which the iPhone and iPad are a primary gateway are usually designed to be as addictive and time-consuming as possible, as many of their original creators have publicly acknowledged,” adding that “it is both unrealistic and a poor long-term business strategy to ask parents to fight this battle alone.”

The growing mound of research

Then in November, researchers at Penn State released an important new study that linked social media usage by adolescents to depression.

At the beginning of the study, a baseline was established with standard tests for depression, anxiety, social support and other issues, and each group continued to be assessed throughout the experiment.

The text above is a summary, you can read full article here.