“Kids now never disconnect,” he said. “They’re connected 24/7. They go to bed with their smartphones. It may be cyberbullying. It may be envy. Maybe many things are going on here.”

One thing the research didn’t find was a link of teen suicides to the opioid crisis. Instead, in school-age adolescents, it found a rise in suicide attempts during school months — September until December, then again January through May — that doesn’t happen in adults.

The rise in attempted and completed suicides by young people correlates directly with their access to smartphones, Dr. Twenge said. “Developmentally, these ages have always been difficult, but that’s been taken to the next level by smartphones, social media and the constant pressure to be online.”

“Eighty-five percent of teens are looking at social media,” she said. “There’s less face-to-face time spent with friends. It’s now the norm to sit home Saturday night on Instagram. Who’s popular and who’s not is now quantifiable by how many people are following you. Kids are spending as much as eight hours a day on social media, where there’s a lot of negativity, competition and jockeying for status and unfiltered access to sites that tell them how to harm themselves.”

Dr. Ackerman, who noted that “young brains are less adept at dealing with complex situations,” likewise believes social media plays an important role in the suicide crisis among the young. But he sees the problem more broadly and said there is a need for schools to help counter it. Staff can be trained and screening done within schools, he said.

“Ultimately it’s a combination of economic, social and technological factors that come together along with family and school issues, and kids are less equipped to tackle these problems,” he said.

Sleep, or rather, not enough of it, is another issue undermining the resilience of today’s teens.

Several studies have found a link between “problematic internet and social media use and sleep disturbance among youth,” and that “these associations contribute to depressive symptoms in this group,” Dr. Twenge and co-authors reported in the Journal of Abnormal Psychology.