Scientists at the University of Pennsylvania may have finally proven what people have suspected for years: Social media is bad for your mental health.

Okay, maybe that’s a little exaggerated, but professors Melissa Hunt, Rachel Marx, Courtney Lipson, and Jordyn Young at UPenn’s psychology department found that decreasing social media usage can reduce feelings of depression and loneliness. It may also reduce a person’s narcissistic and other self-centered behavior.

The study, published in the Journal of Social and Clinical Psychology, delved into the social-media habits of 143 University of Pennsylvania students over a period of several weeks. Half the students used Facebook, Instagram, and Snapchat like they normally would, while the other half restricted their usage to 10 minutes a day. Both groups where evaluated throughout the course of the study on seven different scales measuring moods and psychological well-being.

The group that significantly restricted their social-media usage demonstrated improved mental health, while the other group showed signs of increased depression and loneliness.

Participants in the study noted feeling happier when they used social media less. “Not comparing my life to the lives of others had a much stronger impact than I expected,” said one student. “I felt a lot more positive about myself during those weeks.”

This report breaks new ground in the study of social media and its effects on human behavior because prior studies only found a correlation between social media and depression, whereas the work at the University of Pennsylvania demonstrates that social media may be the cause of depression.

More work needs to be done to determine the cause and effect of such behaviors, but we already have the evidence we need to prove that over-reliance on social media is harming our society. Many people in today’s youngest generation, who never knew a world without social media, have become so entranced by the power of social-media platforms that they make most decisions based on gleanings from the online world.

Depression, loneliness, and attempted suicides among adolescents have risen sharply since 2010. There is also a steep rise in the number of people suffering from narcissism. These are not just people who are stuck on themselves in the classic sense; these are people so self-absorbed that it negatively impacts their lives and their ability to have functional relationships with other people.

Social media does have value. It can help spread information, it keeps us connected with people, and it can bring together people of common interest who might not otherwise connect. However, the creators of these platforms have designed it in such a way as to make it addictive.

Facebook’s “like” button, which has since been copied by many other social media platforms, is a perfect example. What started out as a simple feature to show approval for someone’s post became a craving for affirmation. Very quickly, people drew a direct connection between how many “likes” they received with their sense of self-worth. Instead of sharing information on social media for the sake of sharing it, people began crafting posts specifically to draw positive responses from others. The number of likes or followers a person collected on social media inflated or deflated their self-worth, skewing their sense of self-importance, and hampering their ability to negotiate social interactions.

As we have said many times, on platforms like Facebook and Twitter you are the product. The goal of these companies is to rope you in, collect as much data on you as possible, and use that data to make money, either by selling your data outright to third parties or by selling you products or services. The platforms will tell you whatever you want to hear and show you whatever you want to see to keep you coming back.

One way to combat the problem is to exercise personal responsibility and treat social media more like a disease. Throughout history, one of the best ways to combat disease was nutrition. The same can be done for social media.

Proper nutrition creates a healthier body and a stronger immune system, making it harder for disease to take hold. The same can be done for the mind, making people more resilient to the ill effects of social-media addiction. Examples of this include engaging in critical thinking, healthy skepticism to group ideas, and using common sense. That can protect you from the mass hysteria, fake news, and narcissistic impulses that social media so easily breeds.