The psychologist David Rosmarin recently treated a patient who was still grieving over the devastating car wreck that had left her infant niece a quadriplegic more than 13 years earlier.

The woman was unable to get past the tragedy. If God had allowed such a thing to happen to an innocent child, she reasoned, then anyone, herself included, could be struck down at any time. The thought filled her with anxiety, and she was losing her faith.

While an earlier generation of psychologists might have treated her anxiety with traditional therapies—and referred her religious questions to a spiritual adviser—Rosmarin, a faculty member of the department of psychiatry at Harvard University and an assistant psychologist at McLean Hospital in Belmont, Massachusetts, took a different approach. He decided to incorporate his patient’s faith into a regimen of cognitive behavioral therapy, using their sessions to help the woman think about God’s influence on the world in a more positive way. After weeks of therapy, her anxiety was reduced and she was eventually able get off medication.

Rosmarin is among a small but growing number of psychologists who are blending religion and spirituality with more traditional therapies to treat patients for conditions ranging from anxiety and depression to addiction and grief. Recognizing the growth of this approach, the American Psychological Association last year released a two-volume handbook on best practices for using spirituality in a therapeutic setting.

Many of the early figures in psychology were interested in spirituality as part of therapy, but during the 20th century practitioners began to move toward a more science-based approach. Freud considered religion infantile and wrote about it with distaste throughout most of his career.

But Kenneth Pargament, editor of the APA handbook, says the goal of treatment is to restore patients’ sense of control during seemingly uncontrollable situations. And increasingly, he says, psychologists recognize the power of religion and spirituality to help patients cope with life’s challenges without becoming hopeless and depressed.

“Religions of the world have, for millennia, helped people come to terms with finitude,” Pargament says. “Religions are organized around the basic reality of human limitation.”

Spirituality can be used in combination with psychology in a host of ways. Therapists can guide patients through a meditation practice as a tool to reduce anxiety, introduce the concept of ritual bathing to provide a sense of spiritual cleansing, or encourage patients to attend religious services for greater social and emotional support during bouts of depression.

This practice isn’t only for deeply spiritual people, and it’s not about making converts. Prior to creating his program at McLean, Rosmarin asked patients about the importance of spirituality in their lives. Thirty-seven percent responded they weren’t affiliated with a particular religion but were interested in including spirituality in therapy. More than 50 percent indicated that religion or spirituality was important to them in some way.

“Many patients feel that the more spiritually connected they are, the less anxious they feel,” Rosmarin says. “If they have a sense there is a higher being looking out for them and taking care of their day-to-day life, what is there to worry about?”