Research at the University of North Carolina has found that being lonely is as harmful to teenagers’ health as not getting enough exercise:
http://www.abc.net.au/news/2016-01-06/study-finds-teenagers-loneliness-bad-for-their-health/7070376
http://www.pnas.org/content/early/2016/01/02/1511085112.full.pdf
http://www.pnas.org/content/early/2016/01/02/1511085112.abstract
http://onlinelibrary.wiley.com/doi/10.1111/soin.12018/abstract
