He gives his name as Robert, he played Division I college football for four years, and he is worried about the effects of multiple concussions. He had some outbursts, “rage” in his word, and some of his football friends have as well. For a long time he figured this was an unfortunate part of playing the sport – the aggression of it. Then he heard about legendary NFL linebacker Junior Seau committing suicide and being diagnosed post-mortem with CTE, the brain disease linked with concussions. Suddenly more of his symptoms made sense: maybe CTE is having an effect on him.

“I think it does, just to be honest,” Robert says. “Other athletes I talk to, I know guys with straight depression, thinking suicidal thoughts. Sometimes I have them. I don’t know where they come from. I think CTE does take you to a darker place.”

It’s that darker place that has many doctors very worried.

CTE has become a catch-all reason for troubling symptoms in many athletes. It makes a lot of sense: if you played football or another contact sport, and if you had hits to the head, then maybe you have CTE. It’s impossible to know for sure – at this point, CTE, or chronic traumatic encephalopathy, can be diagnosed only post-mortem – but it’s also impossible to rule out. That has driven a lot of people to excessive fear, experts say.

“There are a lot of people who are convinced they have this condition,” says Beth Pieroth, a Chicago-based neuropsychologist who treats athletes from high school to the pros. “Even those who are not retired pro athletes. The most distressing thing is when you have athletes with a history of one concussion, or two, who are coming in having decided they have CTE and their life is now over. It’s incredibly distressing.”

This kind of concern is becoming common all over the country, according to more than a dozen experts interviewed for this story.

At a concussion conference of neuropsychologists in Cleveland in April, Dr. Summer Ott stood before a room full of colleagues and asked: “Is there a hysteria around concussions?”

Many in the audience nodded.

In her own experience, Ott, an assistant professor of orthopedic surgery with McGovern Medical School at UT Health, has seen an increasing number of teenage athletes come to her office with the near-certainty that they have CTE. One told her, “I probably have CTE,” as if he was resigned to it.

After Ott’s speech, Donna Broshek, president of the Sports Neuropsychology Society that put on the conference, was asked how many of the 200 or so members present think appropriate concern over concussions has tipped into fear.

“Everybody,” she says.

And it’s not just the doctors in that room in Cleveland, or even the doctors in the country. Lili-Naz Hazrati, a pathologist at Toronto’s Hospital for Sick Children who studies athletes’ brains regularly, has the same worry.

“Athletes are thinking all their problems are CTE,” she explains. “This disease is relentlessly haunting them. I get a lot of phone calls, people saying, ‘I’m sure I have CTE and I’m suffering from it.’ It has made a lot of people desperate.”

Hazrati tells the story of an amateur athlete who suffered from depression and memory loss. “He could not take care of the symptoms,” she says. “They were overwhelming.” In a search for answers, he read about CTE and figured it must be that. He ended up taking his own life.

His brain was sent to Hazrati, who examined it and found no CTE. The young man had vasculitis, which is treatable.

“That is tragic to me,” she says. “It shows what is going on out there.”

What is going on out there is not just the awareness of CTE, which is a great thing. It’s also the presumption of CTE, which is creating emotional problems of its own. And some of the responsibility of that shadow lies with the forces that helped us become aware of CTE in the first place.

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Over the course of the past six years, a string of events have thrust CTE into the public consciousness: the suicides of Seau and Dave Duerson; Boston University’s 2015 groundbreaking study that revealed CTE in 87 of 91 deceased NFL players’ brains it examined; the release of the movie “Concussion”; and the NFL’s concussion settlement and subsequent public acknowledgment of a connection between football and CTE.

Today, an otherwise obscure scientific discovery is common knowledge in the majority of American households. According to a Yahoo Sports/YouGov poll, 60 percent of adult Americans are aware of CTE, with most learning about it through media reports. Of those, 43 percent believe there’s a “high chance” of getting CTE if you play high school football. The number grows to 83 percent for the NFL. And among the symptoms respondents believe have definitively been linked to CTE, 50 percent cited suicidal tendencies.

The concern is very real, and why not? Media coverage of a series of tragedies and the concussion issue overall has raised awareness and helped the push toward better safety measures at all levels of athletic play – from youth all the way to the pros. Yet in some cases the reporting has been misleading if not alarmist, according to some experts.

“The media reporting of CTE has been a little bit unbalanced,” says Hal Wortzel, associate professor at the Colorado School of Medicine. “Every time there’s a diagnosis it’s a news piece on CNN. The public hears about CTE as if it’s a definitive scientific conclusion.”

In a search online for the term “What is CTE?”, one of the first results returned will be a Washington Post video published in May, which tries to break down a complicated subject in just two minutes. Near the middle of the clip, the video states that “Boston University’s CTE Center will study Aaron Hernandez’s brain,” followed by this: “Hernandez committed suicide in his jail cell while serving a life sentence for a 2013 murder.” The clip then shows images of Seau and Duerson, NFL players who “also took their own lives … They both suffered from CTE.”

It’s possible that Hernandez had CTE, but grouping him with Seau and Duerson is a startling leap, one without any scientific basis.

Hollywood took some liberties when it came to the movie “Concussion,” says Dr. William Barr, the director of neurophysiology at the NYU School of Medicine. In one scene, Will Smith, playing the roll of Dr. Bennet Omalu, explains the death of former Pittsburgh Steeler Terry Long this way: “Football gave him CTE, and CTE told his brain to drink a gallon of antifreeze.”

“I’m watching it thinking, ‘Oh my God,’ ” Barr says. “That’s terrible.”

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So what do we scientifically know about CTE? There is confusion and some disagreement on that. The leaders in the field of CTE research, at Boston University, define it this way: “Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease of the brain found in athletes (and others) with a history of repetitive brain trauma, including symptomatic concussions as well as asymptomatic subconcussive hits to the head.” Included in the definition is this passage: “The brain degeneration is associated with memory loss, confusion, impaired judgment, impulse control problems, aggression, depression, and, eventually, progressive dementia.”

A key phrase there is “associated with,” instead of “causes.” CTE can be diagnosed only after death, so a pathologist sees a brain only after autopsy. That limits the conclusions that can be made about what a person experienced during a life.

“We can never make causal inferences where CTE made [someone] drink or made [someone] commit suicide,” says Kevin Bieniek, a pioneering researcher of CTE based at the Mayo Clinic in Jacksonville, Florida. “You look for patterns. That’s when you say, ‘Look at this trend, look at how strong this is.’ We always avoid the word ’cause’. We say ‘associated with.’ ”

It’s an important distinction. Experts say psychological symptoms like depression can derive from anything from drug abuse to marital problems to financial struggles to post-career emptiness – not only hits to the head. But those life issues are usually temporary; CTE is often seen as a dead end.

“Every doctor you talk to can give you a story about people who have given up,” Pieroth says. “If you tell someone they have CTE, that’s a death sentence. People are being told that. So they think, ‘Why bother? My brain has rot.’ I am desperately worried about college and pro athletes who become convinced they have this condition and kill themselves. I’m terrified of that.”

At the Mayo Clinic in Jacksonville, Bieniek authored a key study that examined the brains of patients who suffered from dementia. He found 66 athletes out of thousands of brain donors by looking through old yearbooks and obituaries to see which of the deceased had played sports. He found 21 of those 66 had CTE, while none of the non-athletes had CTE. Concerning? Definitely. But since all of the patients studied had some form of dementia, it’s impossible to tell what symptoms the CTE may have caused. And it’s impossible to tell if CTE impacted their quality of life, and to what extent.

“The attention CTE has gotten has been good as far as spurring interest and research that wasn’t there,” Bieniek says. “The flip side is when people are inundated, there’s this bias as far as thinking, ‘I have this now. I have football and concussions, and I’m forgetting things.’ ”

The inundation is not from boring research papers; it’s from sad headlines. Just about every post-mortem diagnosis makes national news and many turn into long feature stories.

The leading voice on CTE is Dr. Ann McKee at Boston University. She is often quoted in news stories about the disease and was a top expert in “League of Denial,” the award-winning PBS documentary about football and traumatic brain injury. McKee says she has studied 352 brains of deceased athletes and military and found 256 cases of CTE – roughly 72 percent. That’s a high percentage, but it’s important to note that nearly all of those who pledged their brains to Boston University had serious problems during life. McKee readily acknowledges “a selection bias in who we evaluate after death.”

Beyond that, 256 cases is a small amount of brains compared to the millions of people who play contact sports around the world. By way of comparison, Hazrati in Toronto has examined roughly 30 brains of athletes and found less than a third tested positive for CTE. She even found one CTE-positive in a man who had no history of traumatic brain injury or contact sports. In her mind, Boston’s initial finding of 87 positive diagnoses out of 91 has had a disproportionate effect.

“We’ve made a whole story based on 90-something people,” she says. “Maybe they [Boston University] have studied 300. But it’s a whole study with huge societal, personal, and financial impact all over the place based on a small number of people. We have drawn conclusions that seem to be clean and clear but they’re not.”

In May, the U.S. Department of Veteran Affairs put on a BrainTrust Summit and highlighted McKee as the featured speaker. It was a chance to underscore the need for more CTE research. She told the audience “there are millions of innocent people that are at risk.” She said even those with early stages are “very symptomatic” and show “irrational behavior … personality changes … often suicidality.”

Reached by phone after her speech, McKee was asked how often suicidality is found in her subjects. “It’s a common symptom,” she said. “I don’t think we know how often. More than half.” But when asked if millions are at risk for suicide, she said, “We’re not there yet. That’s the concern. We have a lot more studies to do. There’s evidence that things like lifestyle and economics have something to do with CTE. We’re not ready to make sweeping statements.”

But sweeping statements like, “Millions of innocent people that are at risk” make for a better headline than, “We have a lot more studies to do.”

Late last year, when discussing the CTE diagnosis of former NFL fullback Kevin Turner, McKee told the Associated Press that although it’s not possible to determine whether the disease caused the late Turner’s ALS, “this is the best circumstantial evidence we will ever get.” A founder of the Concussion Legacy Foundation, former pro wrestler Chris Nowinski, said, “What Kevin Turner’s case shows is that when you start playing football at 5 years old, and you’re successful, it destroys your brain.”

That could sound frightening to someone like Robert, the former college football player struggling with symptoms. He started playing at age 8 and was quite successful. Has football destroyed his brain?

The science says: not so fast.

“Yes CTE has been seen in college athletes and high school athletes, but these are a few anecdotal cases,” says Daniel Perl, a neuropathologist at the Uniformed Services University of the Health Sciences in Maryland. “How extensive this problem is, we don’t know. The concept that a kid who gets a concussion is at risk and on the way to developing CTE is a real stretch.”

In fact, Perl says, “we’ve got a ways to go” in regards to proving CTE triggers diseases such as Parkinson’s or ALS. CTE, he explains, could be an instigator, an accessory, or simply present in the brain while other factors play a larger role in causing symptoms. Or it could depend on the person.

And yet there is information out there that conflicts with what Perl is saying.

In a New York Times story in 2010, a research paper was cited as suggesting Lou Gehrig may not have had Lou Gehrig’s disease, as he had a history of concussions. The paper didn’t mention Gehrig. “Here he is, the face of his disease,” McKee told the Times, “and he may have had a different disease as a result of his athletic experience.”

It’s possible Gehrig had CTE. We will never know. His body was cremated. But readers of that story were left to wonder: Is ALS actually caused or worsened by sports?

An ensuing editorial, in Muscle & Nerve, objected to the speculation: “Media coverage generated by the McKee et al. study has caused much concern for our ALS patients who now believe they may be misdiagnosed. We want to make it clear to physicians and their ALS patients that reports of Lou Gehrig succumbing to anything but the disease which bears his name are inaccurate.”

You may have heard about the Lou Gehrig story. It’s less likely you heard about the Muscle & Nerve response.

“It is sometimes frustrating,” Wortzel says, “to see the voices saying, ‘There’s a lot we don’t know here’ – their word hasn’t been effectively disseminated in the same way the proponents talking about epidemics have been.”

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“I’ve been diagnosed with [CTE],” former Pro Bowler Leonard Marshall tells Yahoo Sports. “I know there’s data that says you should not be able to diagnose CTE in the living. I think that’s a bunch of crap.”

Marshall, 55, says his life has improved lately, in part because he has avoided opioids in favor of hemp oil. “I’m having a great time right now,” says Marshall, who has pledged his brain for research by the Concussion Legacy Foundation. “I wake up every day, I feel better every day.”

That is heartening news from a football hero, but for younger athletes who think they might have CTE, it might be difficult to decide how to adjust and cope. Suicide is an outcome of hopelessness and one possible cause of hopelessness is the belief that one has an incurable and progressive brain disease. If an athlete concludes that CTE is to blame for symptoms, there’s a parallel conclusion that the damage is already done.

“They see it as a death sentence – something they can’t control,” Ott says. “It’s because of CTE or football.”

So doctors who indicate a CTE diagnosis may be doing unknown harm, experts say. If a former athlete loses sleep over a disease that may or may not be in their brain, that lost sleep can lead to the symptoms associated with CTE: anxiety, irritability, memory loss and despondency. And if you read certain news stories, your future can seem more dire than it needs to be. Meanwhile, a non-athlete who loses sleep might seek help and get it and feel better without giving CTE a thought.

“Anyone who is saying CTE causes suicide is not being responsible,” says NYU’s Barr. “All I say is that a [patient] died and had abnormal pathologies in the brain. In my experience, the medical community has been irresponsible and has looked at the newspapers rather than the journals.”

One study, done before the movie “Concussion” came out, surveyed nearly 7,000 former NFL players about their overall quality of life. The study was conducted at the University of Michigan and “… debunks popular myths and shows that some commonly held perceptions about NFL players are actually misperceptions … It finds a group who are satisfied with life, who are, in general, well-educated with strong social connections to family, friends, and community.” For example, the study finds that “for current depression, the NFL retirees look very similar to the general population at rates of 3 to 4 percent. This is not a trivial problem, but it does not appear to be excessive among NFL retirees.”

This is not to diminish problems specifically faced by NFL players. The study found a higher rate of dementia than the overall population. And former football players face significantly higher levels of pain than most normal middle- to older-aged men. “Rates of arthritis among NFL retirees are nearly five times higher among younger retirees than comparable men in the general population,” the study says, “and twice as high at older ages.”

Obviously a brain injury causes pain, in the short term and sometimes in the long term, but in CTE research it can be difficult to tell which clinical symptoms are made worse by opioid use. “Several studies have shown that chronic opioid analgesic use is associated with increased risk of new-onset depression,” is how one 2016 research paper begins. It goes on to state, “patients with remitted depression who were exposed to opioid analgesics were 77% to 117% more likely to experience a recurrence of depression than those who remained opioid–free.”

Hazrati wonders if opioids’ effect on the brain make CTE worse, rather than the other way around.

“When I look at the brains of young people I’m very surprised to see CTE,” she says. “It’s very focal and here and there. They died of drug abuse and had a history of drug abuse. Maybe they had CTE and were taken over by symptoms and pushed to take the drugs. I cannot find what came first.”

There are other factors also at play, including lifestyle and genetics. It is quite possible, even likely, that some brains are more vulnerable to CTE than others. At Columbia University, neuropsychologist Yaakov Stern is studying “Cognitive Reserve,” where IQ, education and engagement in leisure activities can protect the brain from the clinical effects of neurotrauma.

“Trauma has always been listed as a possible risk to induce dementia,” Hazrati says. “But the link has not been established. With trauma and CTE, nothing has been proven. That link is very circumstantial. We’ve taken a bunch of people and the only thing we have out of there is blows to the head.”

Last month in Cleveland, the final speaker of the concussion conference was a Harvard researcher named Grant Iverson. The title of his talk was “Chronic Traumatic Encephalopathy: A Critical Review.” Iverson spoke softly but his message was clear from one of his opening sentences: “Doubt everything in terms of what you’ve heard and what you think you may know.”

He had only praise for McKee and those in the Boston University group, but he also said he was troubled by the connection between CTE and suicide. “I was so upset,” he said, “at the portrayal of suicide as a characteristic of CTE.”

Iverson showed a slide stating that prior to 2009, “McKee and colleagues did not consider suicidality to be associated with, or a clinical feature of, CTE.” And yet “suicide is now widely cited in the literature as a clinical feature of CTE.”

“We’ve just opened the floodgates to all of psychiatry,” Iverson said. “From mental problems to gambling.”

After the speech, Iverson was asked for an interview and seemed taken aback. “I usually don’t speak to the press,” he said. Subsequent emails and calls have gone unreturned.

“I know there are skeptics,” McKee says, when asked about those who express doubts. “People point to natural aging. I’ve heard many times [CTE] is a product of drug use and steroid use. The overwhelming evidence is that trauma is a major factor in CTE.”

But the evidence as to what CTE itself causes is not as clear. There are troubling symptoms associated with CTE, but direct links are not agreed upon.

It could be argued that all of the caution expressed by Iverson and others serves only to muddy the waters, and that science will eventually show that CTE is both widespread and deadly. It is possible that CTE is the next version of smoking.

But again, some researchers won’t go there.

“This is not really analogous to tobacco,” Wortzel says. “There’s very good science showing smoking leads to lung cancer. When we talk about CTE, we talk about [roughly] 200 brains from highly selected cases. These are people who had a number of things going on in their life, like psychiatric illnesses, substance abuse. Most people do have good recoveries from these [head] injuries.”

That is the most pressing message doctors want to convey: most head trauma, diagnosed and treated properly, will give way to recovery. Most symptoms – especially among young athletes who are already going through emotional and psychological changes – can be treated.

That is the lesson learned by Robert, the college football player with symptoms often associated with CTE. Upon the advice of a family member, he is entering a counseling program.

“There is help out there,” he says. “There’s a different way out than hurting yourself.”