Two large Apple shareholders with a $2 billion stake have written an open letter to Apple. They are questioning the smartphone maker, saying it needs to respond to what’s seen as a “growing public health crisis” of smartphone addiction in young people.

The letter cites studies that show American teenagers receive their first smartphones at the age of 10 and spend an average of 4.5 hours a day on it (excluding texting and talking times). It further states that 78 percent of teens check their phones at least hourly, with half reporting they feel “addicted” to their phones. Apple says it has new features and enhancements in the pipeline to help parents control children’s use of iPhones and other devices. This is an important development in the discussion of how to strike a  healthy balance in your child’s digital world.

If you have attended my parent seminar or read my book, Parenting in a Digital World, you learned the average teen is consuming six to nine hours of digital media a day. This more time than many children are sleeping every night. In a peer-reviewed study that appeared in the journal Clinical Psychological Science, after 2010, teens who spent more time on new media (screens) were more likely to report mental health issues than those who spent time on non-screen activities. The study found kids who spent three hours or more a day on smartphones or other electronic devices were 34% more likely to suffer at least one suicide-related outcome—including feeling hopeless or seriously considering suicide—than kids who used devices two hours a day or less. Among kids who used electronic devices five or more hours a day, 48% had at least one suicide-related outcome.

As a School Resource Officer and as a Behavioral Threat Assessment Investigator, I have been witnessing a growing number of children struggling with depression and anxiety in our communities. In a recent survey I conducted of 350 eighth-grade middle school ...