Authors' reply

Cook & Powell are surprised that our findings run counter to research conducted in the USA. They are also concerned that people may conclude from our data that spirituality is bad for mental health. Rather than bad, our main finding is that a religious or spiritual life view confers no advantage in terms of mental health. Our results are not so unusual. Although reviews have suggested that religious and spiritual beliefs and practices are associated with better mental health, the evidence often comes from poor-quality studies and effect sizes reported are small. This is not surprising from a theological point of view; the idea that religious people are protected from the impact of life's difficulties runs counter to the theology of most major world religions. ¹ Furthermore, the evidence base that spiritually informed therapies are effective is tiny, partly because funding for trials is hard to obtain and there have been very few well-designed studies. Religious belief and practice has its main impact on health through lifestyle habits (e.g. less consumption of tobacco and alcohol) and social support. Also, as Cook & Powell note, the context in Europe is quite different to that in the USA. Professing a religious or spiritual belief in Europe may be regarded as strange or even derisory. Such beliefs and practice are more mainstream in the Americas, although even there the occurrence of such beliefs is declining.

In findings from a large prospective study across Europe, published after this paper, we have shown again that holding a spiritual or religious life view may be associated with later mental health problems, but that the effects are weak. More importantly, however, we confirmed that there was no mental health advantage for such beliefs. ² These prospective data give clues to the direction of the association. It seems that holding a spiritual life view predisposes people to depression. As Cook & Powell say, a spiritual search may often be a ‘lonely one’. However, it remains possible that the search for spiritual answers does not itself cause depression; rather, people already vulnerable to depression search for spiritual answers.