Around 2012, something started going wrong in the lives of teens.
In just the five years between 2010 and 2015, the number of U.S. teens who felt useless and joyless — classic symptoms of depression — surged 33 percent in large national surveys. Teen suicide attempts increased 23 percent. Even more troubling, the number of 13-to-18-year-olds who committed suicide jumped 31 percent.
In a new paper published in Clinical Psychological Science, my colleagues and I found that the increases in depression, suicide attempts and suicide appeared among teens from every background: more privileged and less privileged, across all races and ethnicities, and in every region of the country. All told, our analysis found that the generation of teens I call “iGen” — those born after 1995 — is much more likely to experience mental-health issues than their millennial predecessors.
What happened so that so many more teens, in such a short time, would feel depressed, attempt suicide and commit suicide? After scouring several large surveys for clues, I found that all of the possibilities traced back to a major change in teens’ lives: the sudden ascendance of the smartphone.
Because the years between 2010 and 2015 were a period of steady economic growth and falling unemployment, it’s unlikely that economic malaise was a factor. Income inequality was (and still is) an issue, but it didn’t suddenly appear in the early 2010s: This gap between the rich and poor had been widening for decades. We found that the time teens spent on homework barely budged between 2010 and 2015, effectively ruling out academic pressure as a cause.
However, according to the Pew Research Center, smartphone ownership crossed the 50 percent threshold in late 2012 — right when teen depression and suicide began to increase. By 2015, 73 percent of teens had access to a smartphone.
Not only did smartphone use and depression increase in tandem, but time spent online also was linked to mental-health issues across two different data sets. We found that teens who spent five or more hours a day online were 71 percent more likely than those who spent only one hour a day to have at least one suicide risk factor (depression, thinking about suicide, making a suicide plan or attempting suicide). Overall, suicide risk factors rose significantly after two or more hours a day of time online.
Of course, it’s possible that instead of time online causing depression, depression causes more time online. But three other studies show that is unlikely (at least when viewed through social media use).