Nov. 14 (UPI) -- Researchers believe excess screen time may be increasing symptoms of depression, as well as suicide-related behaviors and thoughts, among teens in the United States.
Scientists found the link between depression and time spent in front of TVs, tablets and phones was especially strong among teenage girls.
"These increases in mental health issues among teens are very alarming," Jean Twenge, psychology professor at San Diego State University, said in a news release. "Teens are telling us they are struggling, and we need to take that very seriously."
According to data collected by the U.S. Centers for Disease Control and Prevention, the suicide rate for females between the ages of 13 and 18 increased 65 percent from 2010 to 2015.
Researchers compared the data with a pair of anonymous surveys conducted since 1991. The surveys polled teens about their health and behavior.
Analysis of the survey and CDC data showed the number of girls who reported severe depression or feeling hopeless has increased, as have the rates of suicide-related behaviors, like planning for or attempting suicide.
"When I first saw these sudden increases in mental health issues, I wasn't sure what was causing them," said Twenge. "But these same surveys ask teens how they spend their leisure time, and between 2010 and 2015, teens increasingly spent more time with screens and less time on other activities. That was by far the largest change in their lives during this five-year period, and it's not a good formula for mental health."
A closer examination of the data revealed a correlation between screen time and suicide-related behaviors. Researchers found nearly half of all teens who reported spending more than five hours on electronic devices also reported at least one suicide-related outcome. Only 28 percent of those who spent less than hour looking at screens reported a suicide-related outcome.
Researchers published their findings this week in the journal Clinical Psychological Science.
Previous studies have shown links between time spent of social media and depression among teens.
"Although we can't say for sure that the growing use of smartphones caused the increase in mental health issues, that was by far the biggest change in teens' lives between 2010 and 2015," Twenge said.