A recent article from National Geographic on why teens behave the way that they do:
http://ngm.nationalgeographic.com/2011/10/teenage-brains/cahana-photography
and some new research being done on the teenage brain:
http://www.healblog.net/health-news/a-closer-look-at-the-teenagers%E2%80%99-minds/
http://www.emckemptville.ca/20111110/lifestyle/The+teenage+brain+-+a+time+of+great+change
http://online.wsj.com/article/SB10001424052970203806504577181351486558984.html
http://parenting.blogs.nytimes.com/2012/05/03/the-evolving-teenage-brain/
http://wrd.mydigitalfc.com/knowledge/teenage-brain-thinks-differently-528
http://io9.com/the-neuroscience-of-why-teenagers-behave-the-way-they-d-1474948786
How teen brains are adapting to modern tech:
http://www.news.com.au/news/tech-age-molds-teen-brains/story-fnepjsb4-1226467576379
And evidence of differences in the brain structure of kids with certain mental diagnoses: