The relationship between religion and mental health can be studied under at least eight broad categories: (a) the influence of religion on the clinical presentation of mental disorders, (b) the relationship between religion and positive mental health, (c) religion as a risk or protective factor for specific mental disorders, and the ways in which such associations are mediated, (d) religion as a component of explanatory models of mental illness, and of societal attitudes and practices towards them, (e) religion as a factor influencing help-seeking and pathways to care for mental disorders, (f) the effects of religion on the outcome of specific mental disorders, (g) religious coping in the caregivers of persons with mental illness, and (h) religious or spiritual approaches to the treatment of mental disorder. It can be concluded that: (a) there are complex relationships between religion and mental health; (b) religion and spirituality can have positive effects on mental health in both clinical and non-clinical populations; (c) religious coping can have both positive and negative aspects; (d) religion can provide an invaluable source of social support, but can also contribute to stigmatization of the mentally ill; (e) the influence of religion may vary according to the type of mental disorder being considered; and (f) religious and spiritual approaches may be fruitfully integrated with medical or psychological treatments for mental disorder.