Number of homeless people with mental illness increased slightly in recent years, but experts say they're more visible: Analysis

There has not been a significant overall rise in the number of people experiencing homelessness over the past decade, according to a new ABC News analysis of data from the U.S. Department of Housing and Urban Development, though there has been a steady increase in the number of people experiencing homelessness with severe mental illness, according to our analysis of HUD data.

However, people experiencing homelessness may be much more visible in public spaces to a degree that outpaces the growth in overall numbers, experts told ABC News. This is due to a combination of factors, including a rising number of people who are homeless and living nearly full time on the street, increased real estate development in some cities, and police action in prohibiting and forcing the relocation of the homeless, all of which experts said can contribute to or exacerbate mental health problems.

"It's more visible in a lot of these cities," Chris Herring, an assistant professor of sociology at the University of California Los Angeles who studies homelessness, told ABC News. "People are moving to new parts of the city and often have to move around more, and are more unstable."

That creates the perception of more people experiencing homelessness and the perception of more severe mental illness, even as the overall numbers are not rising dramatically.

"Homelessness has become more obvious without necessarily becoming worse," Dr. Margot Kushel, M.D., director of the Benioff Homelessness and Housing Initiative at USCF and principal investigator of the California Statewide Study of People Experiencing Homelessness, told ABC News. "It's much more in your face than it was before."

Perception versus reality

The national landscape of homelessness is highly variable across the United States, according to data from the Annual Homelessness Assessment Report produced by HUB. More than half of all people experiencing homelessness in 2022 were in four states: California (30%); New York (13%); Florida (5%); and Washington (4%). California, Vermont, Oregon and Hawaii have the highest rates of homelessness relative to the number of residents, according to HUD data.

But overall numbers have been fairly steady over time. An ABC analysis of HUD data shows that in 2022 there were about 2,000 more people living in homelessness nationwide compared to 2020. Over the last five years, the total number of people experiencing homelessness has increased by 5.7%, but compared to a decade ago, there's been a 6.3% decline. While HUD data is the most nationally representative available that measures the number of people experiencing homelessness, it is only collected on one day per year. Experts say that it's a consistent metric but does not paint a complete picture of homelessness in the US.

However, the relatively stable number of homeless people in the U.S. may now be intersecting with the nation's growing mental health crisis.

ABC News' analysis of HUD data does show some increase in the numbers of people living in homelessness who have a severe mental illness. In 2022, over 122,000 people living in homelessness had severe mental illness – this number has been rising slowly over the last decade, increasing from 108,378 in 2012, according to HUD data.

That small increase of homeless led to a tsunami of calls to 311 and 911, experts said.

Despite overall stability in the population of people experiencing homelessness, people in some cities are more likely to raise concerns about homelessness.

"In many cities we've seen extraordinary growth in using 311 to complain about homelessness that go far beyond the number of people experiencing homelessness," Herring said.

In San Francisco, for example, the number of people homeless and living on the street — considered "unsheltered" homeless — grew by around 1% between 2013 and 2017, according to HUD data.

In that same window of time, the number of 311 complaints for homelessness increased 781%, according to research from Herring published in the journal American Sociological Review. The number of 911 dispatches for homeless complaints increased 72%.

Those calls weren't associated with any crime, Herring said. Based on how the city of San Francisco records 911 and 311 calls, they were calls just expressing "homeless concern."

Similar patterns exist in other cities, he said.

"While annual HUD statistics are informative, the alarming increase in civic complaints in cities like San Francisco, not linked to criminal activities but rather societal concerns, accentuates the heightened visibility of this challenge," John Brownstein, Ph.D., epidemiologist at Boston Children's Hospital and ABC News contributor, told ABC News.

More people who experience homelessness are living on the streets or unsheltered

The most visible group of people experiencing homelessness are "unsheltered homeless" — people who regularly sleep on the streets, in parks, or in vehicles. "Sheltered homeless," on the other hand, includes people who stay in emergency shelters, transitional housing or other safe havens.

ABC News' analysis shows that the numbers and proportion of people experiencing homelessness who are unsheltered, sometimes called "rough sleepers," has been increasing.

"The rise of 'unsheltered homeless' individuals, particularly in states like California, brings to the fore the urgency of the situation," Brownstein said.

Over the past decade, the number of people experiencing unsheltered homelessness has been rising and now accounts for 40.1% of the number of people experiencing homelessness – a historical high compared to 2007 when it reached 39.5%. This is also highly variable across states. For example, California and New York have the highest numbers of people experiencing homelessness in the U.S., but 67% of the unhoused in California were unsheltered in 2022 while 95% of the unhoused in New York were sheltered in 2022, according to HUD estimates.

Kushel says this is likely to play a part in people's perception of homelessness because people experiencing homelessness may be more visible in some cities.

"When I give talks, I say, 'who has more homeless people — New York, or Los Angeles," she says. "Every single person says California or Los Angeles; it seems so obvious to them."

That's because in New York, a bigger portion of the homeless population is sheltered, Kushel says. "They're out of sight."

In 2022, Kushel led the most comprehensive homelessness survey done to date in California. This survey reported nearly 80% of people experiencing homelessness said that they had spent the most time while homeless in the prior six months in unsheltered settings (21% in a vehicle, 57% without a vehicle) and nearly all respondents (90%) reported at least one night in an unsheltered setting in the last six months.

"Such visibility, combined with an increased number of those without shelter, inevitably shifts public perception, underlining the need for multifaceted solutions that address both the root causes and the immediate concerns," Brownstein said.

In addition to more people being unsheltered, more people experiencing homeless are chronically homeless — defined by HUD as continually homeless for a year or more, or with four episodes of homelessness in the past three years.

"Once people become homeless, they stay homeless a really long time," Kushel says.

ABC analysis of HUD data showed 12,768 people were experiencing chronic homelessness in 2022, which is a 47.4% increase in the past five years and a 27.9% increase compared to a decade ago. This now makes up 21% of the population experiencing homelessness, which is a historical high since 2007 when 18.5% of the homeless population experienced chronic homelessness.

Responses to homelessness can also make it more visible

New real estate development in places like San Francisco also contribute to the perception that more people are experiencing homelessness, Herring said.

"Certain areas where unhoused people could exist out of sight, or more safely, or more stably, are being eaten up by development," he said. That development increases the number of workers and commercial businesses in those areas — raising the chances that someone might encounter someone who is unhoused.

Businesses in those areas may be more likely to call 911 or 311 about a person experiencing homelessness. The data sometimes shows daily or weekly calls from the same address, Herring said. That could reflect a security guard calling regularly about a person sleeping nearby, for example, he said.

Increased policing in response to those types of calls, particularly on the West Coast, contributes further to visibility, Herring said. Much of the police response focuses on dispersing people experiencing homelessness and moving them out of certain areas. That forces people to move around more and disrupts sleep, which in turn could exacerbate visible mental health symptoms, he said.

"It could increase problematic behaviors that are more visible," Herring said. "It's different from when someone has a stable camp in a hidden spot."

That visibility creates the impression there are more unhoused people behaving more erratically in U.S cities. However, Herring said that doesn't reflect the underlying numbers — it reflects the changing circumstances that people experiencing homelessness encounter.

Those encounters are also the ones that people remember, and the ones that drive their perception of the underlying problem of homelessness in the US.

"People see the most extreme version of homelessness," Kushel said. "But that doesn't mean that's the extent of the problem."

Dr. Jade A Cobern, M.D., M.P.H., licensed and practicing physician, is a member of the ABC News Medical Unit.

Youri Benadjaoud, MPH, ABC News and Benjamin Rader, PhD, Boston's Children's Hospital contributed data analysis.