Researchers now say they can tell whether people are depressed without even talking to them first -- all they have to do is watch how those individuals use the internet.

In a study conducted at Missouri University of Science and Technology, researchers watched the internet habits of more than 200 students who were later tested for signs of depression.

The researchers then cross-referenced the information, and found that the depressed group had markedly different ways of using the internet than everyone else.

Specifically, those who were depressed frequently switched among applications, used email and chat programs more often, watched more online videos, and played more online games. Study researcher Sriram Chellappan said the haphazard nature of the students' internet usage may indicate trouble concentrating -- a characteristic associated with depression.

Chellappan said he'd like to use his findings to develop software that could analyze internet usage patterns to predict the onset of depression, adding that such software may be useful to counselors on college campuses.

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