On August 28, The Post published a piece by Dr. Nicholas Kardaras,“The Frightening Effects of Digital Heroin,” that was based on his book “Glow Kids.” In it, he argued that young children exposed to too much screen time are at risk of developing an addiction “harder to kick than drugs.” The response was overwhelming, generating more than 3.3 million views on The Post’s website and hundreds of letters from anxious parents. Now Dr. Kardaras writes about this parental revolt against digital heroin and reminds readers of the worst effects of the obsession.

Experienced sailors, Barbara McVeigh and her husband exposed their children to the natural beauty near their home in Marin County, Calif. — boating, camping and adventuring in the great outdoors. None of this stopped her 9-year-old son from falling down the digital rabbit hole.

His first exposure to screens occurred in first grade at a highly regarded public school — named one of California’s “Distinguished Schools” — when he was encouraged to play edu-games after class. His contact with screens only increased during play dates where the majority of his friends played violent games on huge monitors in their suburban homes.

The results for Barbara’s son were horrific: Her sweet boy, who had a “big spirit” and loved animals, now only wanted to play inside on a device.

“He would refuse to do anything unless I would let him play his game,” she said. Barbara, who had discarded her TV 25 years ago, made the mistake of using the game as a bargaining tool.

Her son became increasingly explosive if she didn’t acquiesce. And then he got physical. It started with a push here, then a punch there. Frightened, she tried to take the device away. And that’s when it happened: “He beat the s–t out of me,” she told me.

When she tried to take his computer away, he attacked her “with a dazed look on his face — his eyes were not his.” She called the police. Shocked, they asked if the 9-year-old was on drugs.

He was — only his drugs weren’t pharmaceutical, they were digital.

In August, I wrote a piece about “digital heroin” for the New York Post, and the response was explosive. More than 3 million readers devoured and shared the piece — though not everyone agreed on its message. Some readers felt that the notion of comparing screens and video games to heroin was a huge exaggeration.

I understand that initial response, but the research says otherwise. Over 200 peer-reviewed studies correlate excessive screen usage with a whole host of clinical disorders, including addiction. Recent brain-imaging research confirms that glowing screens affect the brain’s frontal cortex — which controls executive functioning, including impulse control — in exactly the same way that drugs like cocaine and heroin do. Thanks to research from the US military, we also know that screens and video games can literally affect the brain like digital morphine.

In a series of clinical experiments, a video game called “Snow World” served as an effective pain killer for burned military combat victims, who would normally be given large doses of morphine during their painful daily wound care. While the burn patient played the seemingly innocuous virtual reality game “Snow World” — where the player attempts to throw snowballs at cartoon penguins as they bounce around to Paul Simon music — they felt no pain.

I interviewed Lt. Sam Brown, one of the pilot participants in this research who had been injured by an IED in Afghanistan and who had sustained life-threatening third-degree burns over 30 percent of his body. When I asked him about his experience using a video game for pain management, he said: “I was a little bit skeptical. But honestly, I was willing to try anything.” When asked what it felt like compared to his morphine treatments, he said, “I was for sure feeling less pain than I was with the morphine.”

Sure enough, brain imaging research confirmed that burn patients who played “Snow World” experienced less pain in the parts of their brain associated with processing pain than those treated with actual morphine.

The Navy’s head of addiction research, Cmdr. Dr. Andrew Doan, calls screens “digital pharmakeia” (Greek for pharmaceuticals), a term he coined to explain the neurobiological effects produced by video technologies.

‘I feel like there is a war going on against our children. And it’s come so fast that we’re not even questioning it.’

While this is a wonderful advance in pain-management medicine, it begs the question: Just what effect is this digital drug — a narcotic more powerful than morphine — having on the brains and nervous systems of 7-year-olds addicted to their glowing screens?

If screens are indeed digital drugs, then schools have become drug dealers. Under misguided notions that they are “educational,” the entire classroom landscape has been transformed over the past 10 years into a digital playground that includes Chromebooks, iPads, Smart Boards, tablets, smartphones, learning apps and a never-ending variety of “edu-games.”

These so-called “edu-games” are digital Trojan horses — chock-full of the potential for clinical disorders. We’ve already seen ADHD rates explode by over 50 percent the past 10 years as a whole generation of screen-raised kids succumb to the malaise-inducing glow. Using hyper-stimulating digital content to “engage” otherwise distracted students creates a vicious and addictive ADHD cycle: The more a child is stimulated, the more that child needs to keep getting stimulated in order to hold their attention.

Research also indicates that retention rates are lower on screens than on paper and that schools without electronics report higher test scores. And then there’s Finland. A standard bearer of international excellence in education, Finland rejected screens in the classroom. According to Krista Kiuru, their minister of education and science, Finnish students didn’t need laptops and iPads to get to the top of the international education rankings and aren’t interested in using them to stay there.

Yet in the US, there is a national effort to give kids screens at younger and younger ages as parents worry that their little ones may somehow be “left behind” in the education technology arms race — the data be damned.

But not all parents are drinking the screens-are-wonderful Kool-Aid — some are fighting back.

Cindy Eckard, a Maryland mother of two, is launching a grassroots campaign to create legislation to limit screen time in schools and is testifying in front of a state Senate subcommittee hearing this month.

“I was shocked to learn that the Maryland State Department of Education had no medically sound health guidelines in place before they put so many of our children in front of a computer every day . . . The schools keep encouraging more screen time in the classroom without any regard for our children’s well-being,” Eckard told me. “Our children are owed a safe classroom environment, and right now they’re not getting one.”

Some parents are opting out of public schools for less technology-dependent schools. Many Silicon Valley engineers and executives, for example, put their kids in non-tech Waldorf schools.

Others, like longtime educator and consultant Debra Lambrecht, have decided to create new tech-free school models. Debra has created the Caulbridge School, a distinctly “Finnish-style” school that is intended to serve as a template for future schools throughout the country.

“The argument for technology in the earlier grades is often rooted in the fear of children falling behind. It is true that most children will use technology in their jobs and everyday life. It is also true that most children will learn to drive a car,” Lambrecht said. “Certainly we would not give a 7-year-old child the car keys to give them a jump-start to be a more skillful driver. In the same way, we want to ensure children can effectively use technology as a tool and will bring all of their best thinking, creativity and innovation to bear.”

A Long Island mother recently contacted me because her 5-year-old son in kindergarten was going to be forced by the school to use an iPad. When she complained and threatened to pull her son out of school, her school district threatened to call child protective services. I spoke to her school’s superintendent, and he agreed to let her son opt out of using an iPad. But all the other kindergartners still need to use iPads for standardized-testing purposes. That Long Island mother has already reached out to her local legislators.

Related Video Video length 58 seconds :58 Why you need to stop giving your kids 'digital heroin' Why you need to stop giving your kids 'digital heroin'

That seems to be the key. Parents need to educate themselves, find their voices and speak up. If enough parents organize, push for legislation and put pressure on their schools to limit screen time in school — as well as to delay the grade levels that screens are introduced into the classroom — then we might have a chance to slow down this digital epidemic.

Indeed, even the respected AAP (American Academy of Pediatrics) has just this month modified their screen recommendations suggesting more tech-cautious guidelines: Children younger than 18 months, no digital media; ages 2 to 5, no more than one hour daily, to be “co-viewed” with parents.

But many, myself included, think these recommendations still don’t go far enough. Because of what we know about screens as “digital heroin,” I believe that kids below the age of 10 should have no interaction with interactive screens (iPads, smartphones, Xbox). There should be warning labels on such interactive screens that read: “Excessive Screen Usage by Children May Lead to Clinical Disorders.”

Meanwhile, back in Marin County, Barbara pulled her son out of his suburban tech-filled public school and enrolled him in a more rural, less tech-oriented school. So far, she’s seen huge improvements in his behavior.

She just found out last week that all fourth-graders in her son’s new school will begin learning the increasingly popular skill of “coding” to design video games. Even in this rural hamlet school, kids were allowed to play violent video games indoors rather than having to go outside to play during recess.

She is now hoping to get political about this issue and to reach out to legislators to end the digital madness in elementary schools. “I am prepared to go to war with our public education over technology use. This is wrong,” Barbara said with the determined voice of a mother fighting for her child’s life.

“I feel like there is a war going on against our children,” Barbara said. “And it’s come so fast that we’re not even questioning it.”

Dr. Nicholas Kardaras is executive director of The Dunes East Hampton, one of the country’s top rehabs. His book “Glow Kids: How Screen Addiction Is Hijacking Our Kids — and How to Break the Trance” (St. Martin’s Press) is out now.