Recent research has confirmed that teens who spend too much time texting are at risk for other problems:
http://www.nhs.uk/news/2010/11November/Pages/Texting-and-teen-behaviour.aspx
http://www.medicalnewstoday.com/articles/207319.php
http://www.bbc.co.uk/news/health-11720546
http://edition.cnn.com/2010/TECH/social.media/11/10/hyper.texting.teens/
http://www.worldtech24.com/business/sex-drugs-more-common-hyper-texting-teens