This is Ted Johnson's Brain

A former star at the University of Colorado and celebrated NFL linebacker gave himself to football—only to find at the end of his career that he'd lost his mind. Now, at age 36, he's trying to put the pieces of his broken life back together.

"Bro, where's my car?"

Johnson asked me last fall after lunch at a central Boston sandwich shop. "I thought I parked it right here."

I shrugged. Johnson pushed the horn button on his keychain and listened for his Range Rover. Nothing.

"It's gotta be somewhere, bro, we parked right here," he said in his surfer-dude drawl. Johnson slumped his enormous shoulders and again pushed the button. "Bro, I feel like I'm going crazy. But you don't remember where we parked, either, so maybe that means I'm not losing it. Right?"

We walked the street, searching for the SUV. Johnson's forehead furrowed. He pushed the button again and again with no response—until, finally, the Range Rover's horn sounded. A look of relief washed across Johnson's face. "See," he said with a smile, pointing to his skull, "not losing it."

It was one of my first meetings with Johnson, who was less than two months out of Spaulding Rehabilitation Hospital in Boston. In August of last year, the 36-year-old former CU All-American and star NFL linebacker had checked himself into the center at the urging of his doctor, Heechin Chae, an expert on pain and rehabilitation medicine. Since retiring from the NFL three years earlier, Johnson's life—or perhaps, more precisely, his mind—had gone completely to hell.

His list of troubles was ever-growing, and he ticked them off with the sort of matter of factness that one might use to recount a grocery list. He was divorced. Johnson had been addicted to amphetamines. And he suffered from debilitating headaches, depression, and fatigue, the result, he says, of dozens of concussions during a 10-year career as the middle linebacker for the New England Patriots.

For much of his retirement up to this point, he had spent his time inside Room 801 of the Ritz-Carlton residences and in a rented two-story townhouse in Boston, where he locked the door, closed the blinds, and rarely left his bed unless he needed to eat, use the bathroom, or collect one of the four prescriptions he'd become dependent upon. His once robust list of friends had dwindled—folks simply stopped calling because Johnson stopped answering. It was a painful fall from grace for a man who once seemed in the center of it all, with a wife and kids and a job that every American boy who'd ever strapped on a helmet longed to have.

Since leaving Spaulding, which was behind the townhouse where he'd sequestered himself for the previous year, Johnson had stopped using Concerta and Provigil (both stimulants), started an exercise regimen, and had been assigned to a psychologist who'd given Johnson a road map that would, hopefully, guide him back to some semblance of normality.

The idea of having to reattach training wheels to his life was embarrassing for Johnson. At CU, he'd grown from a shy, self-conscious California high schooler into one of the most important cogs in a defense that helped the Buffs to 34 wins and four bowl-game appearances. During his four years as a starter, from 1991 to 1994, Johnson developed into a concrete block of a kid: 6-foot-4 and 240 pounds of pure linebacker who had the unique talent of dispatching offensive linemen 70 pounds heavier and then brutally nailing running backs. The New England Patriots took him in the second round of the 1995 NFL draft. At 22, Johnson became a millionaire overnight.

During a decade with New England, Johnson helped the Patriots to four Super Bowls, three of which they won, and was a defensive captain for three seasons. Over a career that spanned 125 regular-season games, he built a reputation as one of the league's most ferocious run-stoppers. Johnson shattered helmets and bones; he hit running backs so hard that, even surrounded by thousands of raucous fans, the players could hear the runners whimper upon contact. "He looked like a warrior coming off the field," former Patriots linebacker Larry Izzo once remembered of his teammate, "blood splattered on his pants."

But with each hit, Johnson may have been killing himself. "Sometimes I wish Junior would have just blown his knees out and couldn't walk," Ted Johnson Sr. told me earlier this year. "But his brain? Oh boy."