As bad as the latest Mayor’s Management Report made first lady Chirlane McCray’s signature ThriveNYC program look, the truth is worse.

The annual performance review revealed that Thrive fell way short on many of its goals last year despite a $225 million budget. Its mental health first-aid project, for example, managed to train only 50,000 of the targeted 72,000 people.

It surely didn’t help that Thrive can get picky, such as when it withdrew from a mental health first-aid training event — set up to help address the rash of NYPD suicides — simply because pro-cop Blue Lives Matter was a co-sponsor.

Thing is, those eight-hour seminars are themselves a dubious endeavor: Training how to recognize, say, the signs of depression simply doesn’t begin to address the city’s top mental health problem — which is what to do about serious mental illness such as schizophrenia.

Those are the issues that have people ranting in the streets and drive street homelessness and drug abuse while overburdening hospital emergency rooms and city jails.

In March, the city correction commissioner told the City Council that Thrive had no presence in city jails — though nearly half the 8,000 detainees are diagnosed as mentally ill.

Even Thrive’s own executives don’t seem to take it seriously. This week, no Thrive representative showed to testify at a council hearing on police mental health because its executive director was away on vacation. Where was McCray?

Mismanagement is rife. As Politico reported in April, social work recruits in Thrive’s Mental Health Service Corps got paid to sit around while higher-ups designed the training program.

Mayor Bill De Blasio defended Thrive to reporters Wednesday — while still admitting that some things “need to be reevaluated.”

The hard truth is that the $1 billion down the drain on Thrive is an absolute waste of public resources. Heck, it didn’t even launch McCray to stardom, so it’s a failure even as an abuse of public funds.