Ex-NFL player Phillip Adams had "unusually severe" CTE

Details: Adams had Stage 2 CTE and had significant atrophy in his frontal lobes, according to Dr. Ann McKee, who directs the CTE Center at Boston University.

• McKee said that the frontal lobe density was similar to that of former football player Aaron Hernandez, who died by suicide after being convicted of a 2013 murder.
• "The combination of poor impulse control, paranoia, core decision making, emotional volatility and violent tendencies caused by frontal lobe damage could converge to lower an individual's threshold for homicidal acts," McKee said.

The big picture: Researchers are hopeful they can identify a "biomarker" that could definitively say whether a living person has the disease, writes Axios' Kendall Baker.

• More than 315 former NFL players, including 24 who died in their 20s and 30s, have been posthumously diagnosed with CTE, according to McKee, per the New York Times.

What they're saying: "We cannot say that we're surprised by these results. However, it is shocking to hear how severe his condition was," the Adams family, who agreed to send Phillip Adams' brain to be tested for CTE, said in a statement.

Go deeper: The future of CTE and football

If you or someone you know may be considering suicide, contact the National Suicide Prevention Lifeline at 1-800-273-8255 (En Español: 1-888-628-9454; Deaf and Hard of Hearing: dial 711 then 1-800-273-8255) or the Crisis Text Line by texting HOME to 741741.