Boston University doctors announce that 1974 NFL MVP Ken Stabler suffered from chronic traumatic encephalopathy (CTE).

Last year, a woman receiving a post-concussion syndrome evaluation from the most prominent of these Boston University doctors entered a guilty plea on charges of defrauding Boston Marathon Bombing charities of tens of thousands of dollars.

“The majority of this patient’s severe cognitive, somatic, mood and sleep symptoms that have completely disrupted her life are due to her post-concussion syndrome,” Dr. Robert Cantu wrote of Joanna Leigh. “As a result of these symptoms Dr. Leigh is currently and for the foreseeable future disabled from the kind of complex consulting work she has done before the bomb blast injury was sustained.”

But Dr. Leigh never suffered a brain injury from any bomb blast. She completely made it up. The district attorney’s office knew this from surveillance video and other evidence collected. We possess footage of Ken Stabler playing football but not surveillance video of his drunk driving arrests or his use of narcotics. So, we naturally imagine that any maladies that he suffered from stemmed from the heroic activities we watched rather than the shameful ones shielded from view. But CTE, despite the simplistic analysis offered in the media, likely stems from complex causes that may prove to include genetic predispositions, chemical abuse, and other causes atop trauma.

One needn’t read the man’s autobiography—merely look at the cover—to grasp the problem of ascribing Stabler’s purported late-in-life cognitive difficulties solely to football. On the dust jacket of Snake: The Candid Autobiography of Football’s Most Outrageous Renegade there appears an Oakland Raiders helmet overflowing with Stroh’s, Budweiser, Pabst Blue Ribbon, and Schaefer cans. Far more than the activity associated with the former image does excessive drinking cause brain damage. The Snake retired from football in 1984. It’s unclear when, if ever, he retired from alcohol.

The question of whether chemicals may facilitate the neurodegenerative condition remains much discussed in medical literature. “Little is known about the neuropathological findings potentially associated with other common medical and neuropsychiatric conditions that appear with some regularity among patients with CTE,” Dr. Hal Wortzel of the University of Colorado School of Medicine writes, listing “drug and/or alcohol abuse” among them. Stabler, like Junior Seau, Mike Webster, and others diagnosed with CTE, abused chemicals. Might they play a role in unleashing the malady? Or did the malady play a role in unleashing the chemical dependency?

We don’t know because we know very little about the disease. When the best in sports medicine gathered in Zurich in 2012, they conceded that they understood neither the cause nor prevalence of CTE. The consensus statement of the 4th International Conference on Concussions noted that

chronic traumatic encephalopathy (CTE) represents a distinct tauopathy with an unknown incidence in athletic populations. It was further agreed that a cause and effect relationship has not as yet been demonstrated between CTE and concussions or exposure to contact sports. At present, the interpretation of causation in the modern CTE case studies should proceed cautiously. It was also recognised that it is important to address the fears of parents/athletes from media pressure related to the possibility of CTE.

The Boston University group releasing their CTE findings on Stabler just days before a vote on his Hall of Fame candidacy admits limitations to their research in the scholarly articles they publish. The Center for the Study of Chronic Encephalopathy’s Brandon Gavett, Robert Stern, and Ann McKee wrote in Clinics in Sports Medicine that “the incidence and prevalence of CTE is currently unclear.” The reason for this, which hasn’t changed since the publication of this article, is because no group studying the disease has yet attempted an actual cross-sectional or longitudinal study. Instead, they ply the public with anecdotes that may tell us something about individual players but say very little about their sport. “To date, there have been no randomized neuropathological studies of CTE in deceased athletes,” the article reads, “and as such, there is a selection bias in the cases that have come to autopsy.” In other words, families of former athletes, or, in Stabler’s case, the athlete himself, who exhibit cognitive difficulties in life donate brains—and the postmortems rather unsurprisingly find issues with the brains of these men. It’s kind of like going into a Bernie Sanders for President headquarters and polling those inside on their favorite candidate.

How many football players who lead long, healthy lives suffer from CTE? Is the condition common among non-athletes without a history of trauma? What, specifically, causes the disease?

Individual autopsies of great players such as Ken Stabler, who died of colon cancer and not a neurodegenerative condition, do nothing to answer these and other important questions. Only a randomized study can begin to provide answers. That takes time, money, and labor, and rewards the researchers with publicity only at great cost.

BU received major attention from both ESPN and The New York Times, two outlets driving the Fourth Estate’s CTE obsession, this week as a result of the Stabler story. It advanced the narrative but not the science.

The postmortem diagnosis also likely enables Stabler’s heirs to collect a massive amount of money from the NFL as a result of the lawsuit settled between the league and the players suing it. Stabler joined that suit, and another against equipment manufacturer Riddell even though he wore a Wilson helmet on the cover of Sports Illustrated and on various football cards (a Riddell helmet does grace the cover of his memoir). Did he suffer brain injuries exclusively wearing a Riddell helmet and avoid them wearing Wilson? Did years of partying or years of playing catch up to him? Did the NFL or Alabama or high school football or age cause the neurological issues his family noticed that he suffered from?

Unlike the cause of hoaxer Joanna Leigh’s “brain injury,” Ken Stabler receiving a postmortem CTE diagnosis leaves us without a definitive explanation. In that sense, it’s not unlike the other dozens of confirmed cases of a disease still awaiting real studies to determine prevalence, cause, verified symptoms, and even what damage in the brain even constitutes CTE.

What we know about CTE is that we don’t know much.