"Recovery," "permanently ruined"—these are not words one typically encounters when discussing a contemplative practice.

On a cold November night last fall, I drove to Cheetah House. A former student of Britton's, I joined the group in time for a Shabbat dinner. We blessed the challah, then the wine; recited prayers in English and Hebrew; and began eating.

Britton, an assistant professor of psychiatry and human behavior, works at the Brown University Medical School. She receives regular phone calls, emails, and letters from people around the world in various states of impairment. Most of them worry no one will believe—let alone understand—their stories of meditation-induced affliction. Her investigation of this phenomenon, called "The Dark Night Project," is an effort to document, analyze, and publicize accounts of the adverse effects of contemplative practices.

The morning after our Shabbat dinner, in Britton’s kitchen, David outlines the history of his own contemplative path. His first retreat was "very non-normal," he says, "and very good … divine. There was stuff dropping away … [and] electric shocks through my body. [My] core sense of self, a persistent consciousness, the thoughts and stuff, were not me." He tells me it was the best thing that had ever happened to him, an "orgasm of the soul, felt throughout my internal world."

David explains that he finally felt awake. But it didn't last.

Still high off his retreat, he declined an offer to attend law school, aggravating his parents. His best friends didn't understand him, or his "insane" stories of life on retreat.

"I had a fear of being thought of as crazy," he says, "I felt extremely sensitive, vulnerable, and naked."

Not knowing what to do with himself, David moved to Korea to teach English, got bored, dropped out of the program, and moved back in with his parents. Eventually, life lost its meaning. Colors began to fade. Spiritually dry, David didn't care about anything anymore. Everything he had found pleasurable before the retreat—hanging out with friends, playing music, drinking—all of that "turned to dirt," he says, "a plate of beautiful food turned to dirt."

He traveled back and forth from Asia to home seeking guidance, but found only a deep, persistent dissatisfaction in himself. After "bumming around Thailand for a bit," he moved to San Francisco, got a job, and sat through several more two- and 10-week meditation retreats. Then, in 2012, David sold his car to pay for a retreat at the Cloud Mountain Center that torments him still.

"Psychological hell," is how he describes it. "It would come and go in waves. I’d be in the middle of practice and what would come to mind was everything I didn't want to think about, every feeling I didn't want to feel." David felt "pebble-sized" spasms emerge from inside a "dense knot" in his belly.