With each mass shooting, Americans look to one grim indicator — the number of dead — as a measure of the destructive impact. But damage left behind by gunshot wounds reverberates among survivors and families, sending mental health disorders soaring and shifting huge burdens onto the health care system, a new analysis of private health insurance claims shows.

In 2020, gunshot wounds became the leading cause of death for children and adolescents in the United States. Though the government does not systematically track nonfatal gunshot wounds, existing evidence suggests that they are two to three times as common as fatal ones. These wounds can be especially catastrophic in children, whose bodies are so small that the amount of tissue destroyed is greater.

“What comes after the gunshot is so often not talked about,” said Dr. Chana Sacks, co-director of the Gun Violence Prevention Center at Massachusetts General Hospital and an author of the new study, published on Monday in the journal Health Affairs. The study, which analyzed thousands of insurance claims, maps out lasting damage to families and communities.

  • For families in which a child died of a gunshot wound, surviving family members experienced a sharp increase in psychiatric disorders, taking more psychiatric medications and making more visits to mental health professionals: Fathers had a 5.3-fold increase in treatment for psychiatric disorders in the year after the death; mothers had a 3.6-fold increase; and surviving siblings had a 2.3-fold increase.

  • Children and teenagers who survive gunshot wounds become, as Dr. Sacks put it, “more like lifelong patients.” During the year after the injury, their medical costs rose by an average of $34,884, a 17-fold increase from baseline, driven by hospitalizations, emergency room visits and home health care, the study found.

  • Children and adolescents who survived the most severe gunshot wounds, requiring treatment in an intensive care unit, struggled considerably. In that group, diagnoses of pain disorders increased 293 percent, and psychiatric disorders increased by 321 percent.

The study examined medical records from 2,052 children who survived gunshots, 6,209 family members of children who survived, and 265 family members of children who died from gunshot wounds, comparing each with five controls. Because the study was based on private insurance claims, it did not reflect the experience of families who were uninsured or on public insurance.

Rising costs linked to firearms injuries make it “increasingly an economic issue,” said Dr. Zirui Song, an associate professor at Harvard Medical School and co-author of the study. The prevalence of gunshot wounds has quadrupled over the last 12 years in the population covered by private insurance, he said.

In a paper published last year in the Journal of the American Medical Association, Dr. Song calculated the annual cost of firearms injuries in lost wages and medical spending as $557 billion, or 2.6 percent of gross domestic product. The new study is the first to focus on the cost of nonfatal gunshot wounds, he said.

“The cruel reality is that if one dies from a firearm injury, one is free to society — there’s no more health care spending, no more taxpayer dollars, no more resources used,” he said. “But actually surviving a firearm injury is quite expensive to society. The magnitude of that was previously not known.”

National data on nonfatal gunshot wounds is “disturbingly unreliable,” but many survivors face long-term disability, said Dr. Megan Ranney, an emergency room physician and the dean of the Yale School of Public Health, who was not involved in the study.

“It may be that they have been shot in the intestine, or through a major blood vessel, it could be a bullet has gone through their lung,” Dr. Ranney said. “It can also be that they’ve been shot through the head or the spine.”

Trauma physicians have long observed the ripple effect of shootings on the health of family members and communities, she said, often because of repeated visits to the emergency room for nightmares, anxiety or depression, but “we’ve never been able to measure it.”

Clementina Chery, a Boston woman whose 15-year-old son was fatally shot in crossfire in 1993, and who founded the Louis D. Brown Peace Institute, an organization to support families who have lost members to gun violence, said she had often seen survivors struggle with addictive behavior, job loss, suicidal or homicidal thoughts in the years after a young person dies.

“In that immediate aftermath, I just felt that I was having an out-of-body experience,” Ms. Chery said. She turned to alcohol, she said — “a little wine here, a little wine there” — and found it difficult to leave her house. Her marriage ended. What finally woke her up, she said, was realizing that her younger children were starved of attention.

“I literally was going through the motions,” she said. “I was not living. It was like, what do you call it, a mechanical robot.”

The ripple effect of gunshot wounds is important because these injuries tend to be concentrated in specific communities, usually communities of color, where many young people know someone who has been shot, Dr. Sacks said.

She traced her interest in the subject to the 2012 mass shooting at Sandy Hook Elementary School in Newtown, Conn., where the 7-year-old son of her cousin was one of 20 children killed. The child’s death “changed my life” and has continued to shape extended families and communities in the years that followed, she said.

“We can’t think about this as a problem that starts and ends with the bullet going in and then the acute surgical care,” Dr. Sacks said. “Leaving the hospital is just the beginning of that family’s journey, and I think we need to treat it that way.”