Keeping track of one's emotions and journaling seem to be recommended left and right, and to some degree I have some anecdotal experience with the value of stopping and composing my thoughts with regards to emotions. While I never manage to keep a written diary, I do gain a lot of emotional value from talking or "writing" things out in my head (as well as from watching this video - it gets extra points for the hidden marching band).
What was especially thought-provoking to me about about the study (the paper is titled "The Therapeutic Value of Adolescents' Blogging About Social–Emotional Difficulties"), is that the "results showed that
participants maintaining a blog signiﬁcantly improved on all measures. Participants writing about their difﬁculties in blogs open to responses gained the most" (quote from the study's abstract). How interesting that being open to commentary could be more effective at helping teens deal with their emotions.
For me, this also points out how important it is to be available to listen to teens (and provide support through "commentary"), whether that be in person, through a blog, or other social media. Or, for that matter, any other technology that is coming around the bend.