Social media and networking sites like Facebook, LinkedIn and Instagram have transformed nearly every aspect of human interaction. These changes are even more embedded in both our private and professional lives during the COVID-19 pandemic. What’s less clear is whether our social media habit is entirely a good thing.

Social media use has been associated with an increased incidence of depression, but it’s not clear whether the use of such sites is itself a cause of depressive symptoms over time, or whether depressed people are more attracted to social media sites. It’s a “chicken or the egg”-style debate on correlation vs. causation.

For young adults still developing their identities, the urge to compare oneself against the ticker of carefully-selected positive images posted on social media may lead to feelings of inadequacy and inferiority and precipitate depression.

In other words, does scrolling social media make us depressed, or do we overload on Instagram because we’re depressed?

The first large national study of its kind to track changes in social media use and depressive symptoms over time is a step toward answering this question. Researchers from the University of Arkansas followed almost 1000 young adults aged 18-30 for six months, charting their social media use and symptoms of depression.

They found that individuals who spent 300 minutes or more on social media sites per day were more than 2.8 times as likely to develop depression compared to those who logged on 120 minutes or less per day. People who were already depressed when they started the study did not show a significant increase in social media use, a finding that strengthens the argument that social media use itself may be the causal factor in the onset of depressive symptoms for some.

As to why it is that technologies designed to keep us connected to our personal network seem to be actually making us more depressed and disconnected, the study’s author, Brian Primack, suggests that “excess time on social media may displace forming more important in-person relationships, achieving personal or professional goals, or even simply having moments of valuable reflection.” Put simply, too much engagement with social media distracts us from doing the things that really protect mental wellness such as quality time with friends and family, exercise and making the effort to develop skills and interests.

Social media feeds are often likened to a highlight reel, curated to emphasize only the happy moments of life. For young adults still developing their identities, the urge to compare oneself against the ticker of carefully-selected positive images may lead to feelings of inadequacy, inferiority and anxiety, precipitating depression.

The study population (aged 18-30) had largely grown up with social media as a normalized part of their daily lives. These findings may partially explain why this Millennial/Gen Z population experiences rates of depression up to 17 percent.

Not only is social media potentially depression-forming, it is likely also habit-forming. Social media and related technologies have been shown to produce changes in the brain that are comparable to those changes seen in the brains of people with substance use disorder, gambling addiction and other compulsive/addictive behaviors. Not only is social media potentially depression-forming, these findings suggest it is likely also habit-forming, with technology addiction affecting up to 6 percent of the global population, and rates as high as 10 percent in some countries.

The changes produced in the brain from social media use include a decrease in gray matter in the amygdala, the region of the brain which regulates impulsivity and conditioned responses to negative environmental stimuli.

By keeping your social media use to no more than two hours per day, the study found the risk of developing depression decreased significantly.

Understanding the mental health risks of too much social media use can help individuals make informed choices and set healthy limits for their own use. Keeping track of your own social media use for a few days is a good place to start. If you find yourself consistently clocking more than 5 hours on social media every day, you may want to take steps to reduce your use. By keeping your social media involvement to no more than two hours per day, the study found the risk of developing depression decreased significantly.

Major depression is the leading cause of disability worldwide and accounts for more disability-adjusted life years than any other mental illness or disorder. This represents a huge burden of disease as well as a major public health concern, especially if something as widely popular as social media could be contributing to the epidemic rates of depression.

If you or a loved one are struggling with depression and aren’t sure how to get help, call the National SAMHSA Hotline.

The study is published in the American Journal of Preventive Medicine.