Until his retirement, Andrew Sims, former president of the United Kingdom’s Royal College of Psychiatrists, was professor of psychiatry at the University of Leeds. Having also served as founding editor of “Advances in Psychiatric Treatment” (1993-2003) and of “Developing Mental Health” (2002-2005), he knows something about psychiatry and mental health.

He is also a committed Christian, and his book “Is Faith Delusion? Why Religion is Good for Your Health” (Continuum, 2009) brings those two facets of his life together to confront a common prejudice.

A standard British psychiatric textbook from the mid-20th century illustrates that prejudice: Religion, it declares, is for “the hesitant, the guilt-ridden, the excessively timid, those lacking clear convictions with which to face life.”

However, Sims counters on the basis of his own psychiatric practice as well as a large number of scientific studies, “people with religious belief, rather than being timid and lacking clear convictions, have a greater sense of direction and feeling of independence from control.”

Indeed, one of the major themes of his book is that “religious belief tends to be associated with better health, both physical and mental.”

“The advantageous effect of religious belief and spirituality on mental and physical health is one of the best-kept secrets in psychiatry, and medicine generally," he writes. "If the findings of the huge volume of research on this topic had gone in the opposite direction and it had been found that religion damages your mental health, it would have been front-page news in every newspaper in the land!”

Moreover, Sims contends, “churches are almost the only element in society to have offered considerate, caring, long-lasting and self-sacrificing support to the mentally ill,” which is one of the reasons why “religious involvement results in a better outcome from a range of illnesses, both mental and physical.”

Generally too, he observes, “religion encourages a broadly healthy lifestyle and members of a church or other faith groups are more likely to co-operate with medical treatment.”

“There is no evidence to suggest that seeking religious affiliation for its potential health benefits alone would be advantageous,” he said.

Still, Sims summarizes, in the majority of scientific studies, religious involvement correlates with enhanced well-being, happiness and life-satisfaction; greater hope and optimism, even when facing serious diseases, such as breast cancer; a stronger sense of purpose and meaning in life; higher self-esteem; better responses to bereavement; greater social support; less loneliness; lower rates of depression and faster recovery from depression; reduced rates of suicide; decreased anxiety; better coping with stress; less psychosis and fewer psychotic tendencies; lower rates of alcohol and drug abuse; less delinquency and criminal activity; and greater marital stability and satisfaction. A strong faith and the positive relationships and thinking associated with church membership fortify the immune system, “thus reducing the risk of cancer, improving general health and protecting the cardiovascular system.”

“When looking at the overall effects of religious belief and practice on whole populations,” he writes, “there is substantial evidence that religion is highly beneficial for all areas of health, and especially mental health.”

Indeed, correlations between religious faith and improved well-being “typically equal or exceed correlations between well-being and other psychosocial variables, such as social support.” And, he adds, this substantial assertion is “comprehensively attested to by a large amount of evidence.”

“In one well-conducted study,” Sims reports, “almost 3,000 women who regularly attended church services were assessed for health status, social support and habits. When they were followed up 28 years later, their mortality over that period was found to be more than a third less than the general population.”

Furthermore, “An inverse relationship has been found between religious involvement and suicidal behaviour in 84 per cent of 68 studies. That is, those with religious belief and practice are less likely to kill themselves. This association is also found for attempted suicide; believers are less likely to take overdose or use other methods of self-harm.”

“The nagging question we are left with is, why is this important information” — “epidemiological medicine’s best-kept secret,” he calls it — “not better known?”

“It is a mystery why … government and other authorities are opposed to seeking help from religious organizations.” Also, “it is extraordinary and tragic that the findings of this large body of research … are not better known. If it were anything other than religious belief or spirituality resulting in such beneficial outcomes for health, the media would trumpet it and governments and health care organizations would be rushing to implement its practice.”