DEAR DOCTOR K: My teenage daughter jokingly said she's "addicted" to her smartphone. I didn't find her remark funny because there's too much truth to what she said. Do I have a valid cause for concern?
DEAR READER: Real addiction -- such as to narcotics -- causes changes in brain chemistry. I'm not aware that such changes have been shown for smartphones. But regular users of smartphones (of any age) surely can become very dependent on their phones -- and very anxious when they are not able to use their phones for even a few hours.