Curtis Penfold got kicked out of his apartment, fired from his job, and left Brigham Young University all in the same week.

He left BYU—a private university operated by The Church of Latter-day Saints—because he had started to disagree with some of the Church’s views, causing tension between him and school officials. His exit from the school caused him to lose his on-campus job, and he subsequently resigned from the Mormon Church. Resigning from the church resulted in getting kicked out of his religiously-affiliated private housing, and he received angry emails from old friends and phone calls from his disappointed parents who said he “lost the light” and “used to be so good.”

“I felt so hated by this community I used to love,” Penfold said.

Penfold originally went to BYU to be around fellow Mormons. But over the course of the two-and-a-half years he spent there, he started to find the lack of LGBT rights in the church distasteful and was unable to reconcile the idea of a loving God with the evil he saw in the world. This loss of faith in God went beyond his separation from Mormonism, leading to months of depression, anxiety over the prospect of no afterlife, and suicidal thoughts. He’s better now, but for a while there were days when he wouldn’t even leave his bed.

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.

“When you were five years old and learning English, you never stopped to ask your parents why you weren’t learning German,” said Ray, who uses cognitive behavioral therapy to decatastrophize the concept of hell for clients. “You just learn it. The same is often true of religion. When you’re taught about hell and eternal damnation at ages four through seven, these strong concepts are not going to easily leave you. Just like it’s hard to unlearn English, it’s hard to unlearn the concept of hell.”

Dr. Marlene Winell, a California psychologist and author of Leaving the Fold, compares leaving religion to post-traumatic stress disorder (PTSD). She even created a term for it: religious trauma syndrome (RTS), which she defines in an article for British Association for Behavioural & Cognitive Psychotherapies as “struggling with leaving an authoritarian, dogmatic religion and coping with the damage of indoctrination.” Not every deconvert goes through RTS, but she writes that like PTSD, the impact of RTS is “long-lasting, with intrusive thoughts, negative emotional states, impaired social functioning, and other problems.” RTS is not recognized by the Diagnostic and Statistical Manual of Mental Disorders, though, and some critics say it is just PTSD, applied to religion.

Any negative experiences after leaving religion, from depression to social isolation, can take a toll on your physical health. Isolation, according to a six-year study out of the University of Chicago, can cause health problems such as disrupted sleep, elevated blood pressure, and a 14 percent greater risk of premature death. Depression can cause fatigue, trouble concentrating, headaches, and digestive disorders; and persistent anxiety can cause muscle tension and difficulty sleeping, according to the Anxiety and Depression Association of America. Anxiety is also sometimes linked to stomach ulcers, said Dr. Javier Campos.

Campos, a family practice doctor in Kerrville, Texas, says he will sometimes ask patients about their spiritual lives, if he thinks it’s affecting their health or if they’re going through the loss of a loved one. He’s observed a link between his patients’ thoughts on the afterlife and their physical health.  

“If you have this thought of hell and that you’re going to be punished for unbelief, it [sometimes] translates into other sematic symptoms, such as headaches, anxiety, and needing to be on medication to sleep,” Campos said.

There are now several resources to help combat negative health outcomes after leaving religion, beyond taking medicine for the symptoms or seeing a therapist. Recovering From Religion has monthly support groups across the world and is about to offer a phone hotline for those struggling with deconversion. Journey Free, an organization based in the San Francisco Bay Area, offers an online support group for deconverts and weekend retreats where small groups come together to help and support each other. There are even groups that are essentially atheist churches, where deconverts can go to find weekly community in a nonreligious context.

Not every recent deconvert necessarily needs these resources, though. Some who leave religion become healthier than they were before. This was the case for Annie Erlandson.

Raised Evangelical Christian in Lincoln, Nebraska, Erlandson developed anorexia at age nine, modeling after her pastor father, who wrote a book about his own eating disorder. But Erlandson’s struggles with food were tied to her beliefs. She was petrified of growing into womanhood, fearing she would cause men to lust after her and sin. She thought if she could prevent her first period, she could prevent growing breasts and minimize sin. Finally at age 15, doctors caught on to her persistent low weight and diagnosed her with anorexia.

After this, Erlandson began doubting Christianity, and eventually, she lost her faith.

Like Erlandson, some people’s health improves after deconverting because they stop practicing negative health behaviors that may have been tied to their religion. For example, leaving a faith such as Christian Science, which dissuades medical treatment, obviously opens up more opportunities for healthcare intervention.

Other negative health behaviors sometimes associated with being religious, according to social psychologist Dr. Clay Routledge in Psychology Today, are cognitive dissonance (consistent religious doubts can harm your health) and avoidant coping. An example of the latter is the attitude that things are “all in God’s hands,” which could potentially keep people from taking action on behalf of their own health.

Unlike those who become isolated from community after losing their faith, Erlandson’s social life improved drastically after her deconversion. She began hanging out with theatre kids and people in the local punk rock scene.

“I never really had a social group when I was a Christian,” Erlandson said. “I tried joining a youth group and just never felt like I connected with them. I remember one time, when I was nine, being in church during a hymn and everyone was singing and raising their hands and closing their eyes. I didn’t feel it. This wave of isolation and trepidation came over me. Everyone seemed engaged except for me. I knew I was not like everyone else.”

But not everyone's health and well-being improves after leaving a religion. Since for many people, religion means being part of a community, and belief in an afterlife can make death less frightening, leaving that behind can lead to isolation and anxiety. The end of a positive religious experience can lead to a decrease in health, as was the case for Penfold. But leaving a negative religious experience may be a way to boost health, especially if someone has a nonreligious community to support them, as Erlandson did. But one way or another, a person’s faith, or lack thereof, is often so important that it affects physical, as well as spiritual, well-being.