It wasn’t until our exposure to the parent-education sessions at Jonathan’s first treatment center that we awakened to the full horror of addiction’s relentless spiral. Unlike cancer, which can be seen under a microscope, addiction works away at the brain much more covertly, using the brain’s own flexibility against it.

As Sam Quinones writes in his book Dreamland, the morphine molecule has “evolved somehow to fit, key in lock, into the receptors that all mammals, especially humans, have in their brains and spines ... creating a far more intense euphoria than anything we come by internally.” It creates a higher tolerance with use, and, Quinones continues, exacts “a mighty vengeance when a human dares to stop using it.” What starts as relief of physical or mental pain transforms into a desperate need to avoid withdrawal.

Treatment was tedious for Jonathan, due to long periods of boredom and his discomfort at being required to reach out to others and talk about himself. But he knew he needed help to recover. Over 16 long months, we saw him almost miraculously begin to pull out of the abyss. We were gradually getting our son back. We watched as his brain recovered and he turned back into his old self. He was more communicative, he was happy to see us when we visited, and he even led a 12-step Alcoholics Anonymous meeting once a week.

In his last few months in treatment, Jonathan sought and earned his emergency-medical-technician qualification. He said he wanted to use it to help others, especially young people, avoid his experience. He was so proud that he had found something he loved to do. It was one of the very few things that would light him up in a discussion, so we brought it up with him whenever we could.

Based on his steady progress in recovery, and his successful completion of the rigorous EMT certification program, we thought Jonathan was ready to reenter normal life, and we believed that he deserved the chance. Together, we decided he would attend the University of Denver, which had granted him a gap year after high school. Thanks in part to a sympathetic admissions counselor who had an experience with addiction in her own family, the school agreed to allow him to enter in the fall.

The members of his incoming class were required to read J. D. Vance’s Hillbilly Elegy over the summer and to write an essay about a person who had had a profound impact upon their life. Jonathan wrote powerfully about encountering a man in the grip of an overdose-induced cardiac arrest in a McDonald’s bathroom during the first ride-along of his EMT training. He said the experience had made him realize how precious life is. “I never found out his name,” he wrote, but the experience had made him see his life “in a whole new light.”

Sadly, the morphine molecule had burrowed deeper into his brain than we understood. Even as he was writing his moving essay, referring to himself as a former addict, his relapse was already one week old. Such is the Jekyll-and-Hyde nature of the disease of addiction.