The relationship between psychiatry and religion is complex and takes many forms. Some religions oppose psychiatry because the practices involved in psychiatric healing go against related religious beliefs. The opposite may also be true, and mental health professionals may denounce religions for brainwashing or other dangerous activities. Psychiatry and religion can also be related in a positive manner, in which mental health is seen as part of spiritual health.

Religions may oppose psychiatry for a variety of reasons, including the assertion that faith is the only road to a healthy mind. Scientologists famously denounce psychiatry as corrupt and hold exhibitions demonstrating torturous activities perpetuated by psychologists. Even within a religion, some members may believe that psychiatry is acceptable for some illnesses but not others.

Psychiatry and religion are also related by psychiatry's insights into religion. In some cases, severe mental illnesses are interpreted by religious people as prophecies or visions of the divine. When there is a medical diagnosis for these problems, religious fervor may be reduced in the individual. Some psychiatric research also posits explanations for human culture's belief in religious figures, which can also be highly threatening to religions.

In some situations, a psychiatrist's practice can be influenced by religion. Buddhist psychiatrists, for example, often attempt to incorporate thoughtful meditation into other psychiatric exercises. Likewise, Christian psychiatrists running Christian practices may attempt to involve prayer in the healing process, although limitations are sometimes placed on what religious activities are considered acceptable for a psychiatrist. Involving faith in psychiatric healing is problematic because both the patient and the psychiatrist must share ideas about religion in order for this to be an effective approach.

One interesting relationship between psychiatry and religion is that of rivalry. Both religion and psychiatry are seen as forms of healing the mind and finding mental peace. People who practice religion still often believe that psychiatry better addresses some problems, like severe mental illness. Even so, for problems like general unhappiness or dissatisfaction with life, psychiatry and religion appear to be in competition for solving these problems.

From the perspective of patients, psychiatry and religion may be related in an even more complex manner. Deciding which problems are appropriate for faith and which require medical attention can be difficult when problems lie in the mind. Often, people with similar problems can find relief in either place. Most religions do not forbid psychiatry as a treatment for mental illness, so most patients have no qualms about combining religion and psychiatry into a complete treatment program that adequately meets their needs.