The threat of chronic traumatic encephalopathy (CTE), a degenerative brain disorder that has been linked to the kind of concussive and sub-concussive impacts common to football, continues to be a major issue for the NFL. Players are increasingly aware of the potential of developing the condition, which can produce symptoms such as memory loss, personality changes, depression and suicidal thoughts.

Researchers are working on methods to diagnose CTE in living patients, but it currently can only be confirmed through posthumous examinations of brains. However, Redskins quarterback Kirk Cousins recently said that if a test did exist, he would take it.

“I think there are other guys who would say, ‘I’m going to play, regardless; CTE is not going to change the way I approach the game, so why would I want that hanging over my head?’ I’m in a different position as a QB,” Cousins told Sports Illustrated, which asked several NFL players about the disease and published their comments Wednesday. “My head’s not getting hit every play. There are things I can do to avoid that — slide, get out of bounds.”

Assuming reliable tests for CTE are eventually developed, the NFL might find itself in a tricky situation. Studies of brains donated by families of deceased former football players have indicated that the condition could be afflicting a large number of active players, who then might think twice about continuing to play if they learned they had CTE or were on a path to developing it.

Cousins told SI that if he tested positive for CTE, he would retire. “It’s all about timing,” he said. “If this had been 2015 or ’14, I may have said, ‘Look, I’m on the cusp of financially being able to help my family; I’m going to stick it out a few more years.’

“But if you’re in Year 9, 10, 11, and you’ve done a lot of good things, then I think the decision-making changes. It’s a fluid situation depending on where you are in your career.”

Seahawks defensive end Michael Bennett told SI that he, too, would retire if he tested positive, while Lions linebacker Tahir Whitehead said he would “consider” it, citing “a wife, [and]  three sons.” Whitehead added that “it would be a good idea to make [a CTE test] a part of youth football and to have people get periodically checked.”

Steelers cornerback Artie Burns stated flatly, “I definitely know I have it. I’m going to [test positive for] CTE. I don’t need a test. Is it going to tell me how much I have? We play a physical sport, man. Humans are not made to run into each other.”

Burns is not the first player to claim that he likely has CTE. Former Chiefs running back Larry Johnson, recently told The Post’s Kent Babb the same thing, saying that he suffers from symptoms such as paranoia and self-destructive and violent impulses, and that he can’t remember two entire seasons in which he played.

“Certain things happen in your life,” Johnson, 38, said, “that you just can’t come back from.”

“I can’t lie, we’re all scared,” former Broncos running back Terrell Davis said in August, shortly before being inducted into the Pro Football Hall of Fame. “When I’m at home and I do something, if I forget something I have to stop to think, ‘Is this because I’m getting older or I’m just not using my brain, or is this an effect of playing football?’ I don’t know that.”

“It’s scary to think that my brain could be deteriorating and that maybe things like forgetting a grocery list, or how to get to a friend’s house I’ve been to a thousand times are just the tip of the iceberg,” Hall of Fame defensive end Warren Sapp, in his mid-40s as is Davis, said in June. “ … You try to find a reason that it’s not — that it’s my brain, that I’m not deteriorating right before my own eyes. It’s the most frightening feeling, but it’s also a very weakening feeling because you feel like a child.”

One promising avenue for researchers  involves looking for biomarkers in living patients that can indicate the presence of CTE. Researchers from Boston University School of Medicine announced in September that they had discovered one such biomarker, a protein related to inflammation called CCL11, that may be uniquely “modified in this disease” and could be measured by blood tests.

Other proteins that could be detected in the blood are also under study, including some that help form axons in the brain and are shaken loose by violent collisions. Developing such tests are all the more important, researchers have said, because players are often reluctant to self-report symptoms of concussions for fear of losing playing time and, ultimately, their football careers.

In November, a team from NorthShore University HealthSystem in Evanston, Ill., announced that they confirmed the existence of CTE in a deceased patient whose brain they had scanned four years previously, while he was still alive. The patient was subsequently identified as Fred McNeil, who played linebacker in the NFL for 12 years and who eventually began to show signs of concerning behavior, including depression and a lack of impulse control, and underwent a positron emission tomography (PET) scan at age 59.

“If there’s ever a treatment developed [for CTE], you can test the response to it,” NorthShore co-director Julian Bailes said at the time, noting that CTE forms “a very unique pattern” in brain scans. “If you can trust the scans, you can tell a football player he shouldn’t keep playing, or tell someone in the military he can’t [be exposed to] explosions.”

Johnson, as with many former and current players, said he was jolted by news last month that 27-year-old Aaron Hernandez, the former Patriots tight end who committed suicide while imprisoned on murder charges, was found to have the most severe case of CTE ever seen in a person his age. Panthers center Ryan Kalil, though, told SI that it’s still hard to know just how extensive the disease is among all football players.

“Look, there is no misconception about what we do, that it’s not great for the body, the brain,” Kalil said. “But it’s a choice we make, and we’re more educated now. There are a lot of people who get concussions who don’t play contact sports.

“Whenever they throw out a number — X number of players have been diagnosed with CTE after they’ve passed away — my immediate question is: What does that mean in contrast to the general population? It’s a fairly young issue, and there’s still a lot we don’t know.”

Eagles defensive end Chris Long echoed those sentiments, saying, “I already know football isn’t good for you. At the end of the day, I’m able to do a lot of good things [because of this game]. There’s a give and take with everything.”

“I think it would be the best thing for players if we could all know what we’re getting into,” Long told SI, before striking a hopeful note. “I believe in research,” he said, “and I believe that within a decade or two we’re going to know how to diagnose CTE; we’re going to be able to predict how it manifests. I even think we’ll possibly be able to reverse the effects. I really believe that. … I have faith in modern medicine, and I have faith that the league will eventually figure this out.”

Cousins, however, was wary of CTE tests possibly becoming mandatory for NFL players. “If teams wanted that information I would say, ‘No,'” he said. “I’m not comfortable with that. I don’t want to be cut or traded [because of a positive test].”

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