Like Penfold, many who leave religion in America become isolated from their former communities, which can make them anxious, depressed, or even suicidal. Others feel liberated. No deconversion story is the same, but many who leave behind strongly-held religious beliefs can see an impact on their health.

Americans are less religious than ever. A third of American adults under 30, and a fifth of all Americans don’t identify with any religion, according to a 2012 study by Pew Research (an increase from 15 percent in 2007). But though scientists have studied people who leave cults, research on the health effects of leaving religion is slim.

The most mainstream research on this is a 2010 study out of Pennsylvania State University, which examined data from 1972 to 2006. The study showed that 20 percent of people who have left religion report being in excellent health, versus 40 percent of people currently part of strict religious groups (such as Jehovah’s Witnesses and Latter-Day Saints) and 25 percent of people who switched from a strict religion to a more lenient religion. “Strict” in this study was defined as “high-cost sectarian groups that are theologically and culturally exclusive."

There are some studies comparing the health of religious and nonreligious people. A 2010 study by Gallup showed that nonreligious people are more likely to smoke and less likely to eat healthy and exercise than the faithful. A 2004 study published in the American Journal of Psychiatry showed that religiously unaffiliated depressed inpatients are more likely to display suicidal behaviors than religiously affiliated patients. And a 2011 study in the Journal of Personality and Social Psychology showed that people in economically developed societies tend to have similar levels of subjective well-being regardless of religious affiliation. But studies rarely seem to single out people who have left religion. Even the Penn State study didn’t clarify how recently people had deconverted. Recent deconverts are, understandably, those most likely to see health effects, according to Dr. Darrel Ray.

Ray has been a psychologist for more than 30 years and founded Recovering From Religion, an organization that connects nonbelievers with therapists and each other. According to Ray, it generally takes depressed deconverts two to three years for their health to bounce back. A few years after leaving their religion, they tend to reestablish a social community and rid themselves of guilt they may have felt over premarital sex, depression over losing God, and anxiety about death and hell.

Ray, author of The God Virus and Sex and God: How Religion Distorts Sexuality, said not all of his clients recover within the typical three years, though. Getting over a fear of death after believing in an afterlife for so long takes some of them five years or longer. And about five percent of his clients can take even more time to stop fearing hell. Ray often compares learning about hell to learning a language.