suzanne marques/reporting:"how about you?"kate grinnell and lola karadizian/use smartphones:"yeah. same here. yeah."dr. adam leventhal/university of southern california:"it's everywhere. it's highly accessible. these are high performance, very fast, highly stimulating devices."doctor adam leventhal is professor of preventive medicine and psychology at u-s-c. he and his team did a study to see if teens using their phones excessively... nine hours a day or more... showed signs of a-d-h-d. dr. adam leventhal/university of southern california:"we studied that in a sample of more than 2,500 los angeles area teenagers and we found indeed, yeah, there was a statistically significant link."natsthese boys say everyone they know, is always on their phone. "i'd say half the day, probably, i'm on my phone.""usually when i'm in class, i'm always on my phone too, but i keep up my grades, so i don't think it's a big deal.""most of my peers will bring out their phones once or twice during class -- i'd say -- yeah. i do it too, so i'm guilty of it."doctor leventhal says problem is that parents can

suzanne marques/reporting: "how about you?"kate grinnell and lola karadizian/use smartphones:"yeah. adam leventhal/university of southern california: "it's everywhere. it's highly accessible. these are high performance, very fast, highly stimulating devices." doctor adam leventhal is professor of preventive medicine and psychology at u-s-c. he and his team did a study to see if teens using their phones excessively... nine hours a day or more... showed signs of a-d-h-d. dr. adam leventhal/university of southern california: "we studied that in a sample of more than 2,500 los angeles area teenagers and we found indeed, yeah, there was a statistically significant link."nats these boys say everyone they know, is always on their phone. "i'd say half the day, probably, i'm on my phone." "usually when i'm in class, i'm always on my phone too, but i keep up my grades, so i don't think it's a big deal." "most of my peers will bring out their phones once or twice during class -- i'd say -- yeah. i do it too, so i'm guilty of it." doctor leventhal says problem is that parents can be just as bad