MINNEAPOLIS - You've heard the saying "the eyes are a window into the soul?" Turns out Instagram is a window too.

Researchers with the University of Vermont and Harvard believe they've built an algorithm that can determine whether an Instagram user is showing signs of depression based on their posts to the app.

The tool analyzes which filters are used and, the study found, people suffering from depression were more likely to post pictures with darker colors.

Researchers say this algorithm was accurate 70 percent of the time. Compare that to doctors who are successful at identifying depression in a patient 40 percent of the time.

The studies authors, however, caution their study had a relatively small sample size.

Read the full study, published Monday by EPJ Data Science, here.