This paper reviews research on the relation between religion and (or) spirituality, and mental health, focusing on depression, suicide, anxiety, psychosis, and substance abuse. The results of an earlier systematic review are discussed, and more recent studies in the United States, Canada, Europe, and other countries are described. While religious beliefs and practices can represent powerful sources of comfort, hope, and meaning, they are often intricately entangled with neurotic and psychotic disorders, sometimes making it difficult to determine whether they are a resource or a liability.
Research emphasized that, in the emotionally vulnerable, religious beliefs and doctrines may reinforce neurotic tendencies, enhance fears or guilt, and restrict life rather than enhance it. In such cases, religious beliefs may be used in primitive and defensive ways to avoid making necessary life changes.
However, systematic research published in the mental health literature to date does not support the argument that religious involvement usually has adverse effects on mental health. Rather, in general, studies of subjects in different settings, from different ethnic backgrounds, in different age groups, and in different locations find that religious involvement is related to better coping with stress and less depression, suicide, anxiety, and substance abuse. While religious delusions may be common among people with psychotic disorders, healthy normative religious beliefs and practices appear to be stabilizing and may reduce the tremendous isolation, fear, and loss of control that those with psychosis experience.