Patrick Kennedy, USA TODAY

We’ve all been learning about the cost of not caring about mental illness. The human and financial toll of our nation’s neglect toward the mentally ill is staggering. And directly related to that neglect is the cost of not caring about a growing public health problem: marijuana use.

There has been a lot of talk about pot lately. Discussions of tax revenue, health benefits, violence reduction, and individual liberty. But one issue got completely lost: the developing brains of our children.

It’s about time we start focusing on the rights of our kids, not pot smokers.

As states rush unwisely to legalize marijuana, will this president be remembered for reforming our broken health care system, or for watching the commercialization of a new, legal drug that threatens healthy brain development and the mental health of our children?

That means I don’t want another massive, heavily commercialized drug industry targeting them. Because addiction is a disease that starts in adolescence, industries know they have to focus on young people for profits. After all, if you don’t start using any drug by age 21, you are unlikely ever to do so.

DEBRA SAUNDERS: Pot prohibition just doesn’t work

Now we know why Big Tobacco marketers used cartoons and candy to hook kids. We are seeing the same thing play out in places like Colorado and Washington.

Already, candies, cookies, and lollipops high in THC adorn legal marijuana stores in Colorado and Washington. Never mind that the Poison Control Centers in those two states have reported increased calls for marijuana poisonings, and that kids are getting the message that drug use is OK. After all, it’s legal now.

In other areas of life we tend to rightly put an emphasis on children. We demand better education. We ask that our kids make healthier eating choices. We are expanding health care, including mental health care, to our young people. So how can we, in the same breath, be OK with pot legalization? The marijuana of today is nothing like the marijuana most baby boomers experimented with. It’s virtually a different drug.

So it is no surprise that the president’s own Department of Health and Human Services reported last year that marijuana is the top reason kids are in treatment. It is why I hear about the stories in my inbox from countless parents who are now penniless because they had to spend their child’s college fund on treatment for a drug they first thought was harmless. It is why I hear even more stories from recovering addicts who say, “It all started with pot.”

Thanks to a massive misinformation campaign funded by greed, the gap is wide and deep between what reputable science knows about marijuana’s harms and what the public believes about this drug.

I applaud the president for leading the effort toward reforming our drug laws and emphasizing public health. I salute Attorney General Eric Holder’s smart on crime initiative, which promotes drug treatment courts and other diversion programs for nonviolent drug crimes. We should indeed reform broken laws that disproportionately harm ethnic and racial minorities and the poor. But let’s not replace one tragedy of over incarceration with another — a public health crisis that will hit the most vulnerable the hardest.

And we must not abandon the interests of our kids.

Our country cannot afford another industry that glamorously commercializes addictive drugs, profits from harming people — especially children — and expects the rest of us to pick up the tab for users’ health care and all of the social problems they cause. For every $1 we collect from state and federal taxes on alcohol and tobacco, we spend $10 to address problems stemming from their use. There is no reason to believe marijuana will pay for itself, either.

And the last time I checked, beer and cigarettes — two legal, highly addictive drugs — were pretty easy for kids to get.

Our nation’s future is in the brains of our youth, and they’re getting the shaft — again. Our marijuana debate has been entirely too focused on accommodating drug-using adults, the vast majority of whom would have to admit they first picked up their substance of choice when they were only kids. Their recreational good times have overshadowed our obligations to protect children from drugs.

This is by careful design because so many of the people eager to profit from addiction know the United States’ sentiments about marijuana would change dramatically if we started policy debates with this question: “What is in the best interests of our children?”

I’ll take the best interest of kids over the pot users’ interests — any day.

Patrick Kennedy is a former congressman and an honorary board member of Smart Approaches to Marijuana (Project SAM). This article was published first in USA TODAY.