TORONTO - The degenerative brain disease chronic traumatic encephalopathy (CTE), though it has monopolized the conversation, is not the be-all, end-all outcome athletes who suffer repeated blows to the head should fear.

On Tuesday, members of a panel debating the circumstances and consequences of brain damage in hockey advocated a simpler message: Concussions, whether they cause CTE or not, are inherently harmful and debilitating.

Dr. Brian Levine, a neuropsychologist leading a study tracking the brain health of retired professional hockey players, wants to steer the public conversation, at least in part, toward the treatment of concussion symptoms and psychiatric disorders and away from the "hopelessness" of living with an incurable degenerative condition.

"We already knew, before CTE was discovered in professional athletes, that concussions were bad. And multiple concussions were worse," Levine said at an annual conference hosted by The Rotman Research Institute at Toronto's Baycrest Health Sciences.

"There needs to be perspective that CTE is a very important condition. It's something important to study; it's something I'm studying in my lab. But it's not the only pathology, and it's not the only thing that can go wrong. And, in fact, many other things that can happen from concussions can be treated."

Levine referenced former NHL enforcer Todd Ewen, who died in 2015 at age 49, reportedly of a self-inflicted gunshot. Ewen was said to have suffered from memory loss and depression, but he did not have CTE, which has been linked to concussions and can only be diagnosed posthumously.

"Head injury and concussion is very complicated," said Levine, whose longitudinal study at Rotman has found the NHL alumni involved to be mostly free of significant brain impairment on objective tests, yet reporting high levels of emotional and behavioral issues. "Some people will develop CTE. We don't know who or when or how or what that even means in terms of how it will affect their lives. It's very important; we need to learn that. We already know enough about why concussion is bad for you.

" ... Steve Montador had 19 concussions - that's bad. He ended up getting diagnosed with CTE but someone else might have a similar dose and not develop CTE, but they might have lots and lots of problems. So it shouldn't be just about whether someone has CTE."

Among those joining Levine on the panel at the Sheraton Centre Hotel was hockey icon Ken Dryden, a fierce critic of the NHL's handling of head hits and author of "Game Change: The Life and Death of Steve Montador and the Future of Hockey."

A 10-year NHL veteran, Montador was 35 when he died in 2015 of an undisclosed cause. His history of concussions, and battle with depression and substance abuse, was the focus of a recent installment of HBO's "Real Sports With Bryant Gumbel," examining the NHL's stance on concussions and CTE.

"He was living with significant depression. He was living with real problems of memory," said Dryden, a six-time Stanley Cup champion. " ... Whether he was discovered to have had CTE or not, it was a lousy life the last few years. His life had been affected."

NHL commissioner Gary Bettman has continued to deny a link between concussions and CTE. Meanwhile, a U.S. District Court judge in Minneapolis is currently deciding whether hundreds of former players suing the league over concussions can move forward with their case as a class action.

Dryden wants to "close the gap" between concussion research and decision-making in hockey by narrowing the focus to issues like preventing all hits to the head, which he says are "undeniably" harmful to players.

Levine holds a similarly straightforward viewpoint on brain injury and its lasting impact.

"When you have a significant head injury, let's say from a motor vehicle accident, single blow, serious head injury, over time you lose brain cells," Levine said. "Brain cells die, your brain shrinks - that's bad. If you have multiple concussions, that's a little bit different, then you're getting lots of hits, more hits. Maybe each individual hit isn't as bad as a serious motor vehicle accident, but that also causes brain tissue volume loss.

"So you're losing brain cells. And you're also causing all sorts of other biological consequences: a cascade of neurochemical reactions, hormonal changes, pituitary changes ... it's a complex injury that has multiple dimensions to it.

"One of them is tau (protein) in the brain, which is found in CTE, but it's not the only thing."

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