Mental disorders, religion and spirituality 1990 to 2010: a systematic evidence-based review.

Religion/spirituality has been increasingly examined in medical research during the past two decades. Despite the increasing number of published studies, a systematic evidence-based review of the available data in the field of psychiatry has not been done during the last 20 years. The literature was searched using PubMed (1990-2010). We examined original research on religion, religiosity, spirituality, and related terms published in the top 25 % of psychiatry and neurology journals according to the ISI journals citation index 2010. Most studies focused on religion or religiosity and only 7 % involved interventions. Among the 43 publications that met these criteria, thirty-one (72.1 %) found a relationship between level of religious/spiritual involvement and less mental disorder (positive), eight (18.6 %) found mixed results (positive and negative), and two (4.7 %) reported more mental disorder (negative). All studies on dementia, suicide, and stress-related disorders found a positive association, as well as 79 and 67 % of the papers on depression and substance abuse, respectively. In contrast, findings from the few studies in schizophrenia were mixed, and in bipolar disorder, indicated no association or a negative one. There is good evidence that religious involvement is correlated with better mental health in the areas of depression, substance abuse, and suicide; some evidence in stress-related disorders and dementia; insufficient evidence in bipolar disorder and schizophrenia, and no data in many other mental disorders.