Los Angeles County officials drastically underplayed how many of the nearly 60,000 homeless people living there suffered from mental illness or substance abuse, a new analysis found.

The Los Angeles Times inspected more than 4,000 questionnaires taken as part of the federally mandated 2019 count — and found that 67% of the county’s homeless reported or were observed suffering from mental illness or substance abuse.

That’s compared to the Los Angeles Homeless Services Authority’s tally of the same data, which said 29% of the homeless were mentally ill or abusing drugs.

Mental illness alone, including post-traumatic stress, affects half — 51% — of those living on the streets, the paper found.

The LA agency reportedly reached lower rates by excluding several survey responses.

One omitted question asked: “What do you think are some of the main reasons or conditions that led to your loss of housing?”

“Mental health issues” was one of the multiple-choice answer options.

However, those responses were only tallied if the survey-taker answered “yes” to a follow-up, which asked if their medical condition was permanent or long term.

That omission reduced the rate of mental illness by a whopping 11.4 percentage points.

Interviewers surveying the county’s vagrants during the one-night federally mandated count were asked to note if they observed mental illness or substance abuse. But those comments weren’t included in the public analysis.

If counted, they would have increased the rate of mental illness by 4.5 percentage points and 9 percentage points for substance abuse.

The homeless services authority didn’t dispute the paper’s findings.

It said it came to a different interpretation of the statistics because it had to format its report according to federal guidelines.

“We’re acknowledging that there are more layers to the story,” said Heidi Marston, the agency’s acting executive director.