Active-shooter drills have became common at schools, day-care centers and other places where kids (and adults) gather, now that mass shootings in the United States have become regular events.

As if that statement weren’t horrifying enough, it turns out that babies take part in these things, too, as the following piece explains.

It was written by Heidi L. Pottinger, director of clinical investigations in the Department of Health Promotion Sciences at the University of Arizona College of Public Health, who argues that these drills cause trauma for children.

Pottinger is also the mother of two, and both her children have been part of active-shooter drills since one was 4 months old and the other was 3 years old. She is also the founder of the nonprofit Child Health & Resilience Mastery (CHARM), Inc., as well as a Public Voices Fellow with the OpEd Project, which is a social venture founded to increase the range of voices and quality of ideas that are heard in the public square.

By Heidi L. Pottinger

Eleven people were murdered at Tree of Life synagogue in Pittsburgh in another mass shooting. Nothing can truly prepare us for this violence, whether in synagogues or schools.

Again, we have failed to address preventable gun violence. Dec. 14 marks six years since the Sandy Hook Elementary School mass shooting, when 20 children and six educators were killed. Since that dreadful day, tragedies like this have become horribly routine, and schools continue to practice lockdown drills. We typically associate lockdown drills with school-age children, adolescents, and staff practicing safety protocols.

Sadly, infants and preschoolers also participate.

My daughter has been included in lockdown drills since she was 4 months old. She huddles behind the diaper-changing station with her caregivers and other babies, ranging in age from 6 weeks to 15 months. Down the hall, her brother is hiding with his classmates and teacher. They have been doing this since he was 3 years old and ever since, he’s been anxiously chewing his nails, afraid to go anywhere alone inside our home without an adult. Based on my expertise as a family and child health researcher, he is clearly traumatized.

And he’s not alone. He is one of millions of young children across the nation regularly practicing lockdown drills, huddling behind furniture and inside closets. Meanwhile, their teachers feign complete confidence, strategically managing to keep their beloved young students utterly silent while the clock ticks.

Last week, my husband took our son to a football game, and, after our alma mater scored their first touchdown, they high-fived each other and hugged in celebration. When the fireworks went off, instead of marveling at the spectacle, our son began crying in terror that there was an “active shooter.”

Those were his words. He’s 4.

Children, especially those younger than 6, should not be expected to continue simulating the problem of school shootings by frequently participating in stressful lockdown drills that have not been demonstrated effective, can traumatize them, and potentially impact their education and health outcomes.

While our children and their teachers are usually aware when a lockdown is a drill or “just pretend,” their brains do not, sending their nervous systems into fight, flight, or freeze. Except, they can only do one thing: freeze.

In the short-term, their bodies are overwhelmed with adrenaline and cortisol. This type of unpredictable stress activates inflammatory responses in the body that have been shown to cause depression. For children who also might be suffering from food insecurity and/or fewer opportunities for physical activity, their ability to fight illness is compromised.

Long-term, children are at greater risk for developing chronic illness as adults and, if they experience a life-threatening trauma, post-traumatic stress disorder. Childhood stress is also linked to lower IQ scores and academic achievement. Couple these risk factors with few or no healthy opportunities to manage stress, and lockdown drills are a recipe for disaster for our children.

While lockdown drills provide practical value, they are not always effective — and have actually been used to inform shooters’ tactical strategies.

Our government needs to treat gun violence like the public health crisis that it is. Schools need the resources to substitute burdening children and communities with lockdown drills, with positive behavioral interventions and support for parents and staff, instead. And students need opportunities to release stress hormones immediately after drills.

Let’s equip caregivers and educators with ways to nurture each child to realize their greatness, influencing all children in a positive way. Let’s train adults on how to identify, assess and respond to threatening behaviors rather than distressing entire communities by repeatedly simulating the problem. It would be an investment in our schools and the future of every child.

Such strengths- and evidence-based, personalized approaches might actually prompt our children to learn and be carefree at school — the way it should be — instead of forcing entire generations to hide in silence.

At bedtime, I recently lay beside my son and his new stuffed animal — a monkey named Boris that reacts to touch, motion and sound. When Boris laughed after being snuggled, my son whispered very matter-of-factly before falling asleep, “Shhhh, it’s a lockdown, you need to be quiet."