This led her to study fentanyl-induced amnesia, documented in a 2018 report in the New England Journal of Medicine and observed in a cluster of Massachusetts patients. In some people, fentanyl kills neurons in the hippocampus — a brain area already vulnerable to the oxygen deprivation that occurs during an overdose — by causing cells to fire out of control.

Because the syndrome is so rare, she encountered some doctors who were skeptical about the connection between fentanyl and amnesia. The book traces how others such as Jed Barash, medical director of the Soldiers’ Home in Chelsea, Massachusetts, doggedly pursued answers, ultimately confirming how opioids can damage the hippocampus.

“These Alzheimer’s researchers and neuroscientists are heroes. We owe them a debt of gratitude, because I do think that eventually there will be, if not cures, at least treatments, ”she says.

Currently working on a medical fiction book, Aguirre credits MIT with her willingness to take those leaps. “Just being able to survive there gave me the confidence to believe that eventually, if you work hard enough, you’ll figure things out,” she says.