I'm glad you asked me that question, but I'm not sure that the premise that the link is clear now is one that the scientific and medical communities have embraced. I am not a physician. I am not a scientist. My views are informed by experts in the field. In fact, if you referred to the Berlin consensus statement, the systematic review of the literature published in support of it, it explained:
The causes of mental health and cognitive problems in former athletes, like the general population, are broad and diverse including genetics, life stress, general medical problems (eg, hypertension, diabetes and heart disease), chronic bodily pain, substance abuse, neurological conditions and disease (eg, cerebrovascular disease) and neurodegenerative diseases (eg, Alzheimer’s disease, Parkinson’s disease and ALS).
Accordingly, the systematic review concludes that the extent to which repetitive neuro-trauma contributes to these issues “is poorly understood and requires further study”.
In addition, the consensus statement, which was subscribed to by 36 practitioners in the field, again has continued to say that there has yet to be the ability to draw the conclusion that one will lead to the other.
In fact, Dr. Cantu I believe stated under oath—he is the co-founder of the Concussion Legacy Foundation with Mr. Nowinski, who I believe was here—that we don't know the incidence or prevalence of CTE currently; we don't know the incidence or prevalence of CTE within NHL hockey, and we don't know what the exposure levels of head impacts are for hockey, and that he doesn't have any knowledge to say that three concussions puts you at substantial risk over the course of a career, and that he doesn't have the knowledge to know what the risks are for 15 years of hockey.
In short, based on everything I've been told—and if anybody has information to the contrary, we'd be happy to hear it—other than some anecdotal evidence, I don't believe there has been that conclusive link.