The study, published in the Journal of Affective Disorders, suggested people with a moderate to high level of belief in a higher power do significantly better in short-term psychiatric treatment than those without, regardless of their religious affiliation.
"Belief was associated with not only improved psychological well-being, but decreases in depression and intention to self-harm," David H. Rosmarin, a McLean Hospital clinician and instructor in the Department of Psychiatry at Harvard Medical School, said in a statement.
The study looked at 159 patients, recruited during a one-year period. Each participant was asked to gauge his or her belief in God. Levels of depression, well-being, and self-harm were assessed at the beginning and end of the treatment program.
More than 30 percent claimed no specific religious affiliation yet still experienced the same benefits in treatment if their belief in a higher power was rated as moderately or very high.
Patients with "no" or only "slight" belief in God were twice as likely not to respond to treatment than patients with higher levels of belief.
"Belief in God is associated with improved treatment outcomes in psychiatric care," Rosmarin said. "More centrally, our results suggest that belief in the credibility of psychiatric treatment and increased expectations to gain from treatment might be mechanisms by which belief in God can impact treatment outcomes."