Over the past few decades, there has been a significant increase in the prevalence of depression in adolescents and young adults—and a simultaneous uptick in the inclusion of technology and social media in everyday life. However, it is unclear how exactly social media use and depression are associated and relate to other behaviors, such as physical activity, green space exposure, cannabis use and eveningness (the tendency to stay up late).

In a study published in the International Journal of Mental Health and Addiction, a team of researchers, led by experts at Johns Hopkins Children's Center, investigated the association among social media use, depression and other health-related behaviors of young adults over time.

"Research shows that when social media use is high, depression is also high. But the question is—is that because social media caused that person to be depressed? Or is it because people who are depressed tend to also use social media more, and spend less time exercising and being in green spaces? That is what we wanted to understand," says Carol Vidal, M.D., Ph.D., M.P.H., the first author of the study, a child and adolescent psychiatrist at Johns Hopkins Children's Center and an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.

In their study, 376 young adults in Canada (82.4% women) were asked to complete three online questionnaires between May 2021 and January 2022. At each point, participants self-reported depressive symptoms based on the Patient Health Questionnaire (PHQ-9)—a nine-item scale that is commonly used to measure depression—as well as social media use, greenspace exposure, physical activity and cannabis use.

The researchers found that most study participants had at least mild depressive symptoms. Findings showed that participants who had higher social media use tended to be more depressed, and people who were more depressed also tended to use social media more. However, researchers found that social media use did not cause an increase or decrease in depressive symptom levels over time.

"We found that if you tended to be a person who was depressed, you were a person also spending more time on social media," explains Vidal.

Researchers also found that higher levels of social media use and higher levels of depressive symptoms were associated with lower levels of green space exposure. In addition, cannabis use and higher eveningness were also associated with higher depressive levels.

The study authors say these results show social media use and depression are associated, but do not provide evidence that greater social media use predicts an increase in depressive symptoms over time. The team also says these findings indicate people who suffer from depression should be cautious about the amount of time they spend on social media and should be encouraged to incorporate other healthy habits into their lifestyle.

"Being indoors and not exercising, staying up late and using cannabis has its risks," says Vidal. "It is important for providers to educate patients and for parents to instill healthy habits in their kids—having a balance of moderate social media use and other outdoor activities and exercise is what people should strive for in today's digital age."

Vidal and other investigators believe there are many aspects to social media, and there are important next steps to learn more about its impact on the mental health of people of all ages, including younger children and adolescents.