A new study has found a link between preteens' use of social media and future depression.

The study was conducted by researchers at the University of California, San Francisco,

and published this week in the American Medical Journal's Association Journal, JAMA.

The study said, more time spent on social media may contribute to increased depressive symptoms over time.

Ali Rogan spoke with the lead researcher, Dr. Jason Nagata.

Dr. Nagata, thank you so much for joining us.

Social media, children, lots of questions, few answers.

What did your study find?

We followed 12,000 preteens over three years, and we actually found big rises in social media

use.

So during that period, social media, on average, increased from seven minutes a day to over

70 minutes a day, so a tenfold increase.

And in our analysis, we actually found that rises in social media

from year to year among these nine, then ten, than eleven-year-olds, were actually associated with

future depressive symptoms in the following year. So I think there's a big kind of unknown in the

field right now, chicken or the egg, does social media precede depression or is it maybe just a reflection of

underlying symptoms? And I think that our study does show a little bit more stronger evidence that

social media is a risk factor for future depression in these kids. So what you're saying is that

you found the correlation here to be with social media use leading to more depressive symptoms, not the

other way around. You're saying that depression doesn't necessarily indicate use of social

media. Yes. In our study, we were able to follow these same 12,000 kids year to year.

So we were able to look at both their depression and their social media use every single year.

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