TUESDAY, Nov. 21, 2017 (HealthDay News) -- There's a new sign of mental distress among American girls: Nearly 20 percent more young teen and preteen females have sought emergency room treatment for poisoning, cutting or harming themselves yearly since 2009, research shows.
Girls ages 10 to 14 had an 18.8 percent increase per year in treatment for self-inflected injuries -- the sharpest rise among young people ages 10 to 24, according to an analysis of ER data from 66 U.S. hospitals.
Poisoning was the method used most often, said researchers led by Melissa Mercado. She's a behavioral scientist with the National Center for Injury Prevention and Control at the U.S. Centers for Disease Control and Prevention.
The overall increase in self-harm was more than 8 percent every year among all females studied, Mercado's team found.
No similar upswing was seen among males.
"Self-inflicted injury is one of the strongest risk factors for suicide," said Mercado.
And suicide among youths is a growing problem. "In 2015, suicide was the second leading cause of death among U.S. youth aged 10 to 24 years," she added.
Last week, a study published in Clinical Psychological Science identified a surge in depression incidence, suicidal thoughts and suicide among teenage girls.
That study, led by Jean Twenge of San Diego State University, linked the upswing to time spent online and on social media.
"It is imperative that we determine why so many more girls are harming themselves," said Twenge, a psychology professor who wasn't involved in the current research.
Mercado and her colleagues focused solely on care provided in an ER setting. They believe the numbers may actually underestimate the scale of the trend, given that some young people likely sought care outside of an ER.
The emergency room data came from hospitals across the country. In all, investigators studied more than 43,000 self-inflicted injury-related ER visits between 2001 and 2015. They focused on three methods of self-harm: poisoning, sharp object and blunt object.
Overall, ER visits due to self-harm among boys and girls rose nearly 6 percent since 2008.
Researchers can't say precisely why rates remained stable for males, but jumped so dramatically among girls.
Unfortunately, "the data used in this study does not allow us to understand why rates have increased among females," Mercado said.
"However, these findings are consistent with previously reported upward trends in youth suicide rates during 1999-2014," she noted. Those reports have documented rate increases after 2006, with 10- to 14-year-old females at greatest risk.
"These findings also coincide with increased reports of depression among youth, especially girls," Mercado said.
She stressed that "suicide is preventable."
Clearly, the trends observed "underscore the need for the implementation of evidence-based, comprehensive suicide and self-harm prevention strategies within health systems and communities targeted at young people," Mercado said.
Twenge said the results add to "the mounting evidence for a sudden increase in mental health issues, especially for girls."
Based on her own research, Twenge offered some advice to parents: "Be aware that seeing friends in person is better for mental health than communicating via the phone," she said.
Also, make sure that teens' phones are shut off overnight so they get enough sleep, she said.
"We found that suicide risk factors increased after two hours a day or more of electronic device use, suggesting that keeping use to two hours a day or less is a reasonable limit to set," Twenge added.
The findings appear in a letter to the editor in the Nov. 21 issue of Journal of the American Medical Association.
There's more on parent-child communication at .