A recent meta-analysis, which summarized the results of 147 independent investigations involving a total of 98,975 subjects on the association between religiousness and depressive symptoms, found that religiousness is modestly but robustly associated with lower level of depressive symptoms. Several studies have shown that addressing the spiritual needs of the patient may enhance recovery from illness ( Mueller, et al., 2001). Most studies have shown that religious involvement and spirituality are associated with better health outcomes, including greater longevity, coping skills and health-related quality of life (even during terminal illness) and less anxiety, depression and suicide. The role of spirituality as a resource for finding meaning and hope in suffering has also been identified as a key component in the process of psychological recovery. Some of these are reviewed in this article.
The studies on how religion and spirituality affect the brain, though inconclusive, still give vital pointers to the neural mechanisms of such practices. It is noted that spirituality can have both positive and negative effects on physical health, mental health and coping. Therefore a person may have religion without spirituality or spirituality without religion. Spirituality and religion are not interchangeable or always linked. Though closely related, religions probably originated as a way of meeting humanity's possible innate need for spirituality.
The English word religion comes from the Latin ‘ religio’ meaning reverence, though a deeper study reveals it to be a combination of two words, ‘ Re’ meaning return and ‘ Ligare’ meaning ‘to bind’. Religion is an organized belief system promulgated and sustained by a human institution, ethnic group, tribe or culture and involves definite rules of behaviour, practices and rituals. Religious experience and religion forms only a part of a person's spiritual quest. Spirituality is therefore an individual's experience of and relationship with a fundamental, nonmaterial aspect of the universe that may be referred to in many ways – God, Higher Power, the Force, Mystery and the Transcendent and forms the way by which an individual finds meaning and relates to life, the universe and everything. Spirituality involves as its central tenet a connection to something greater than oneself, which includes an emotional experience of religious awe and reverence. The spiritual realm deals with the perceived eternal realities regarding man's ultimate nature, in contrast to what is temporal or worldly. The English word ‘spirit’ comes from the Latin ‘ spiritus’ meaning breath. The nature of spirit is intangible or immaterial. Spirituality is defined as that relating to or consisting of or having the nature of spirit. This overview highlights the involvement of multiple neural structures, the neurophysiological and neurochemical alterations observed in meditative practices. The neurotransmitter changes contribute to the amelioration of anxiety and depressive symptomatology and in part explain the psychotogenic property of meditation. The neurochemical change as a result of meditative practices involves all the major neurotransmitter systems. Neuroimaging studies have shown that meditation results in an activation of the prefrontal cortex, activation of the thalamus and the inhibitory thalamic reticular nucleus and a resultant functional deafferentation of the parietal lobe. The available data on meditation focus on activated frontal attentional network. The evidence though preliminary and based on studies replete with methodological constraints, points toward the involvement of the prefrontal and parietal cortices. The exact neural basis of these effects is slowly coming to light and different imaging techniques have elucidated the neural basis of meditative practices. Spiritual practices have been proposed to have many beneficial effects as far as mental health is concerned.