(CNN) The number of children and teens in the United States who visited emergency rooms for suicidal thoughts and suicide attempts doubled between 2007 and 2015, according to a new analysis.

Researchers used publicly available data from the National Hospital Ambulatory Medical Care Survey , administered by the US Centers for Disease Control and Prevention every year. From the 300 emergency rooms sampled, the researchers tracked the number of children between 5 and 18 who received a diagnosis of suicidal ideation or suicide attempts each year.

Diagnoses of either condition increased from 580,000 in 2007 to 1.12 million in 2015, according to the study, published Monday in JAMA Pediatrics . The average age of a child at the time of evaluation was 13, and 43% of the visits were in children between 5 and 11.

"The numbers are very alarming," said Dr. Brett Burstein, the lead study author and a pediatric emergency room physician at Montreal Children's Hospital of McGill University Health Centre. "It also represents a larger percentage of all pediatric emergency department visits. Where suicidal behavior among the pediatric population was just 2% of all visits, that's now up to 3.5%."

The findings come as no surprise to child psychiatrists.

"We know that suicide and depression have been rising significantly," said Dr. Gene Beresin, executive director of The Clay Center for Young Healthy Minds at Massachusetts General Hospital and professor of psychiatry at Harvard Medical School, who was not involved in the study.

Depression and a prior suicide attempt are the two biggest risk factors for suicide, and with rates of suicide on the rise, it makes sense for risk factors to increase as well, he explained.

The reason? It's complicated

One reason for the increase in depression and suicidal behaviors may be more stress and pressure on kids, Beresin said.

"Kids are feeling more pressure to achieve, more pressure in school, and are more worried about making a living than in previous years," he said.

Parents and caregivers are also more stressed, Beresin said, adding that rates of suicides have increased in all age groups over the past 20 years and that the stress is passed down to children and teens.

Another reason may be the rise of social media and increasing rates of cyberbullying that have come with it, Beresin said.

Approximately 15% of US high school students report that they've been bullied online in the past year, according to the CDC . A Pew Research Center survey found that the number could be even higher: 59%.

"Cyberbullying can be especially difficult for kids," explained Dr. Neha Chaudhary, child and adolescent psychiatrist at Massachusetts General Hospital and Harvard Medical School and co-founder of Brainstorm: Stanford Lab for Brain Health Innovation and Entrepreneurship. "Unlike in settings like schools, it can fly under the radar without anyone knowing it's happening and without the same repercussions for the bullies."

In isolation, none of these factors has been proven to lead to an increase in suicidal behaviors and ultimately suicide, but taken together, a pattern begins to emerge, Beresin said.

And the country may not be adequately equipped to deal with the problem.

Families left waiting

According to data from the American Academy of Child and Adolescent Psychiatry, the majority of the United States faces a severe shortage of practicing child and adolescent psychiatrists, with fewer than 17 providers available per 100,000 children.

This means many families face long wait times, which can lead to worsening of a child's underlying mental health condition and an eventual need for more treatment sessions than if the condition had been addressed in its early stages, explained Jennifer Mautone, a psychologist in the Department of Child and Adolescent Psychiatry and Behavioral Sciences at the Children's Hospital of Philadelphia.

The available qualified providers face another challenge: communicating with other systems caring for children.

Many systems are aimed at caring for children, including the education, health care, juvenile justice and child welfare systems, said Dr. Barbara Robles-Ramamurthy, a child and adolescent psychiatrist at the Long School of Medicine at UT Health San Antonio who was not involved in the study.

"All of these systems that are supposed to be caring for children oftentimes are not talking to each other," she said. "A lot of times, kids fall through the cracks, and families are not getting the appropriate support they need."

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According to a study published in JAMA Pediatrics in February, half of kids in the United States with mental health conditions like depression and anxiety go untreated.

Rising rates of mental health conditions in youth coupled with difficulties accessing care and long waiting lists is a bad combination, Beresin said.

Burstein, who regularly sees children and teens in the emergency department with suicidal behaviors, worries that the rates will continue to increase.

"We are seeing an acceleration of this issue, and I worry that we have not yet seen the peak," he said.