Mentally ill, and abandoned by N.Y.

There’s danger on New York’s horizon. Kendra’s Law, which keeps 4,000 seriously mentally ill New Yorkers on antipsychotics, mood stabilizers and other violence-preventing treatments, expires in June.

Unless the Legislature makes it permanent or renews it, these sick individuals will be free to leave treatment. Many will then return to the jails, prisons, shelters, streets and institutions. Some will inevitably create mayhem on the way.

What is most striking about this catastrophe-in-the-making is how little the New York mental health industry is doing to avoid it.

Kendra’s Law, named after Kendra Webdale, who in 1999 was fatally pushed onto the subway tracks by a schizophrenic man, empowers judges to order seriously mentally ill people who have strong histories of violence, hospitalization or incarceration to stay in treatment for one year as a condition of living in the community.

Research shows Kendra’s Law cuts homelessness 74%, arrests 83% and incarceration 87%. A study published in 2012 found it saves taxpayers 50% of the cost of care by replacing expensive incarceration and hospitalization with less expensive community treatment.

So why aren’t mental health advocates storming Albany to ensure Kendra’s Law is used more, made permanent, and not allowed to expire?

While researching my book, “Insane Consequences: How the Mental Health Industry Fails the Mentally Ill,” I discovered that the mental health industry largely prefers to treat the highest-functioning and least symptomatic people.

It shuns the seriously ill like those eligible for Kendra’s Law. And this cherry-picking is not just a New York problem; it is a national phenomenon.

As a result, the least ill often go to the front of the line for services — and the seriously mentally ill wind up in jails, prisons, shelters and morgues. A steady stream of new supposed crises like bullying and cyberbullying get attention and funding, while treatment for known serious mental illnesses like schizophrenia and bipolar disorder are ignored.

As a result of the New York mental health system’s systematic abandonment of the seriously ill over the years, our state now has more mentally ill people incarcerated than hospitalized.

It’s not just money that’s lacking, it’s leadership. For example, Gov. Cuomo is continuing to close state psychiatric beds in spite of the fact that as beds go down, incarceration goes up.

Mayor de Blasio’s $850 million ThriveNYC mental health plan is largely focused on improving “mental wellness” in everyone — not treating the 4% of adults who are seriously ill, and potentially a danger to themselves or others.

The mayor dedicated over $2 million to an ad campaign trying to get people who have “anxiety, depression or need someone to talk to” to call a referral line. The ads don’t ask those who are psychotic, delusional and eating out of dumpsters to call.

De Blasio’s mental health department convinced him to spend $6 million training city residents on how to identify the asymptomatic potentially mentally ill — and to cut $500,000 from Fountain House, which serves the known seriously mentally ill.

I’m a Democrat, and not a hater, but as a result of these policies, 40% of the 239,000 New Yorkers with serious mental illness received zero treatment in any given year. The mental hygiene department knows this. It came from their own June 2015 report.

A mayoral task force reported that the percentage of the city jail population with mental illness shot up 30% from 2010 to 2014. And the NYPD’s inspector general documented that calls to the NYPD for emotionally disturbed persons went up 10% from 143,000 in 2014 to 157,000 in 2016.

The fix is simple. Spend less on fuzzy efforts to improve “mental wellness” and more on concrete ones to treat grave mental illness.

Both our governor and mayor have to buck mental health industry trade associations — including the New York Association of Psychiatric Rehabilitation Services and Mental Health America — and open more hospitals, hire more psychiatrists, and fund more programs that serve the people in most urgent need of help.

Most importantly, they should robustly fund Kendra’s Law, fight to make it permanent, and see that more people are enrolled in it. That’s the path to a safer and saner New York.