(CNN) A "huge and largely unreported problem" is happening in ERs across the nation, one expert says.

"The extent to which ERs are now flooded with patients with mental illness is unprecedented," said Dr. David R. Rubinow, chairman of the Department of Psychiatry at the School of Medicine at University of North Carolina, Chapel Hill.

And this overflow is "having a really destructive effect on health care delivery in general," he added. "There are ERs now that are repeatedly on diversion -- which means they can't see any more patients -- because there are so many patients with mental illness or behavioral problems that are populating the ER."

This supports Rubinow's belief that ERs are a major provider of mental health care for a "very, very sizable percentage of patients" these days.

Dr. Catherine A. Marco, from her vantage point as an emergency physician professor at Wright State University in Dayton, Ohio, said, "we commonly see depression, anxiety, substance-related conditions and suicidal behavior."

Firsthand experience suggests to Dr. Mark Pearlmutter, an emergency physician in Boston, that the most common mental health problems in emergency rooms are dual diagnoses, such as "substance abuse and depression, for example." He's also seen cases combining acute psychosis, bipolar disorder, suicidality, aggression and (mal) adjustment disorders.

"We're the safety net," he said.

On the opposite coast, Dr. Renee Y. Hsia, an attending physician at Zuckerberg San Francisco General Hospital and Trauma Center, also finds that the most prevalent psychiatric diagnoses among adults in the ER are alcohol-related disorders, anxiety disorders and suicide or intentional self-harm. Based on her own research of "avoidable" ER visits, she found that two of the top three discharge diagnoses were alcohol abuse and depressive disorder.

"There are very real spillover effects from this phenomenon, which affects not only our ability to care for these patients with psychiatric needs but all patients seeking care in the ER," she said.

In addition to longer wait times for everyone, "spillover effects" include dissatisfied mental health patients and an assumption of potential violence in the ER, according to these doctors.

How one psychiatric patient sees the ER

Sharon Marshall, 43, says her multiple experiences in the ER as a psychiatric patient were "very upsetting."

"They took your phone away, and you couldn't communicate with anybody else in the world," said Marshall, who has been diagnosed with schizophrenia. Being held in the ER for "hours and hours and hours," during which time "you couldn't get your questions answered," means "you have very little control over your circumstances" and "you're at their mercy," she said. "Anybody would be upset."

She believes that her family should have requested outpatient services with her psychiatrist instead of authorizing an emergency psychiatric evaluation that was not voluntary on her part. It was not an arrest; it was a psychiatric hold, she explains.

"If you just play the game and you're quiet and don't pose any problems to them, they'll let you go," she said. "If you questioned being held or resisted ... you'd likely go to a psychiatric facility. The process was so very arbitrary."

Later, a car wreck gave Marshall greater perspective on her experiences as a mental health patient. Arriving in the ER with an arm injury "was like a dream," said Marshall, who works as a certified peer specialist for the Georgia Mental Health Consumer Network, a nonprofit advocacy and education organization. "I was definitely taken seriously when I was in there for a car accident."

David Morris, a psychologist at UT Southwestern's O'Donnell Brain Institute in Dallas, said, "the ER is not a great place if you're a mental health patient; the cardiac patients get put in front of you, and you could end up being there for a really long time." Worse still, a mental health patient could be feeling extreme distress the whole time they wait.

"It's a real ineffective and inefficient place for them to get care," Morris said. "People who need to be seen for other maladies that might be life-threatening, it slows them down as well."

Why is it happening?

A psychiatric bed shortage is one cause of overcrowded ERs

Hsia points to "a shortage of psychiatric inpatient beds" as a "key contributing factor" to overcrowded ERs across the nation.

"Between 1970 and 2006, state and county psychiatric inpatient facilities in the country cut capacity from about 400,000 beds to fewer than 50,000," Hsia said.

A 2012 Wake Forest University Health Sciences study also showed that psychiatric patients who are waiting in ERs remain there 3.2 times longer than nonpsychiatric patients. These longer stays mean that for every psychiatric patient idling in the ER, there are two other patients not being helped, according to the study authors. Patient "boarding" -- holding of a patient in an ER bed while waiting for an inpatient mental health bed -- occurs frequently, the study indicates.

"We've also seen shortages in outpatient mental health facilities and substance abuse treatment programs," Hsia said. Many psychiatric patients who would otherwise receive long-term care are going "relatively untreated" and so end up in ERs, she says. "Patients may come to the emergency department when they cannot find help elsewhere."

One such patient is Karen Taylor, 46, diagnosed with post-traumatic stress disorder and depression. Taylor, who has had suicidal thoughts, says she visited ERs in her home state of Georgia multiple times because she "didn't want [the symptoms] to get so bad that I would actually go so far as to try to attempt suicide."

She was insured and routinely seeing a therapist, and Taylor's various trips to the ER were made out of necessity, she says, because her therapist does not offer after-hours services.

Driven by thoughts of self-harm, she had originally taken herself to a psychiatric hospital, but it would not admit her without the ER referral, she explained in a pained voice.

Emergency departments do not welcome patients like her, says Taylor, who described the ER as "a bad place for a mental health patient."

"They strip away your dignity, your clothes, everything, and the doctor comes in and treats you like dirt because you're taking up a bed," Taylor said. "I was told several times that I was just physically wasting space and I wasn't really sick like the medical patients were.

"They put me in a room where I stayed for hours on end. I've stayed in the ER for up to three days prior to going to a psychiatric hospital."

Mental disorder makes it difficult to access care

UT Southwestern's Morris co-wrote a study that examined psychiatric readmissions at one of the largest public hospitals in the nation, Parkland Hospital in Dallas, with more than 1 million patient visits annually. Nearly three-quarters of mental health patients there were readmitted for the same problem, the study found.

"Most of the patients simply were not able to follow up with their care," said Morris, explaining that the reason for this might be patient confusion about how to access follow-up care or a problem with transportation.

"Organizing the community resources that are out there, they cannot do it themselves," Morris said. "They need the help of a more structured environment. But the more structured environments that used to be available are no longer available."

Asking for help The suicide rate in the United States has seen sharp increases in recent years. Studies have shown that the risk of suicide declines sharply when people call the national suicide hotline: 1-800-273-TALK. There is also a crisis text line. For crisis support in Spanish, call 1-888-628-9454. The lines are staffed by a mix of paid professionals and unpaid volunteers trained in crisis and suicide intervention. The confidential environment, the 24-hour accessibility, a caller's ability to hang up at any time and the person-centered care have helped its success, advocates say.



The International Association for Suicide Prevention and Befrienders Worldwide also provide contact information for crisis centers around the world.

As Morris sees it, if someone had diabetes and ended up in the ER, it would be clear that something's wrong with their ability to handle their condition and care. "That's the issue," he said. "Why are these folks having to do that? Do they need additional management and additional help to maintain the continuity of care?"

Marco, a spokeswoman for the American College of Emergency Physicians, says psychiatrists, psychologists or other licensed therapists are often backlogged; this is why so many mental health patients show up in ERs.

Pearlmutter, the Boston emergency physician, agrees. The reason mental health patients end up in ERs, he says, is due to a lack of "resources within the community and the closure many years ago (20, 30 years ago) of state facilities and, frankly, the fact that mental health is underfunded." Overcrowded outpatient facilities and services mean "patients might call and not be able to be seen for two or three weeks," he added.

"And a lot of this transcends insurance," Pearlmutter said.

In certain regions, patients may call and ask to see a counselor, and the response is that they're not taking new patients, or they don't take insurance and only take cash. "And if they do take insurance, the patient's got to wait," he said. "If the patient's feeling like they're in a crisis, what options do they have? The only place to go is to the ER."

The ER may be the only place to go even for patients receiving routine care.

Assumptions in the ER

Dan Stephens, whose diagnosis is major depressive disorder with psychotic features, sees a therapist once a week and a doctor every three months. Still, on two occasions, suicidal thoughts drove him to the ER.

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"I had zero wait time at the desk. They took me straight back to the mental health section" of the ER, says Stephens, a 39-year-old warehouse worker. Delays occurred as he waited for an evaluation, he says. "The first time, it took me four hours to speak to somebody, the second time about six or seven. They had given me something to calm down, so I had relaxed a little bit instead of being uptight and ready to do harm to myself."

Stephens believes that the ER was necessary given his condition. He accepts longer wait times because, as he understands it, multiple types of doctors are able to care for a patient with a broken bone, but only specialists can treat someone experiencing mental health problems.

Still, one aspect of his two ER experiences was "very humiliating," Stephens said: "The worst part is being escorted to the back by a police officer."

Leaving an ER can also be problematic for mental health patients, according to Stephens: "Usually, you leave in a cop car in handcuffs." A 2016 national survey found that handcuffs were one of the "available tools" used by security personnel in 96% of the hospitals surveyed.

Though he understands why security escorts and restraints might be necessary for some patients, he believes that these measures weren't needed in his case, and he resents their use.

"If I come in of my own volition and say 'Look, I need help,' they should just walk me back there without having to get a cop or security guard," says Stephens, who lives in a small town in Georgia. "People look at you funny, that's what happens."

When he was treated like a criminal, the whole process made him feel worse about himself, he says.

Pearlmutter suggests that doctors may automatically call in help to restrain a patient experiencing a mental health crisis. With overcrowding and more mental health patients, "there's an increase in violence in the emergency department -- absolutely," he said.

What can be done?

One solution to ERs crowded with mental health patients is to do a better job at integrating mental health into medical practice, Pearlmutter says. It's helpful that family medicine and primary care physicians are increasingly providing mental health care, he says, but "we still have a long way to go."

"Payors, by the way, play a role in this," Pearlmutter said. Health care is funded in a manner that promotes a "siloing" of mental health versus physical health. Insured patients, for example, have certain benefits provided for their physical health and separate benefits offered for mental health.

Marco said, "we need more resources, both inpatient and outpatient, for mental health and substance-related disorders. We should advocate for increased funding for treatment of these conditions."

Rubinow says he first wrote about ERs crowded with mental health patients years ago.

"At that time, it was a tsunami on the way," he said. "That tsunami has hit."