That's pretty wild stuff. I have read before how the tone of receiving a text or message gives a similar amount seratonin (the love hormone) released into your body as when you receive a hug. We are set up to feel good about using our phones. At least once we start and become conditioned to them. I recently deleted my Instagram and Facebook from my phone and I would often find myself grabbing my phone and swiping back and forth doing nothing, where I would have previously been on one of the two sites doing the same. Kinda of scary stuff when you think about it.
RE: Does your smartphone create 'brain drain' just by being around you?