This study aimed to evaluate the effects of spirituality on the lifestyle and the percentages of the white blood cells in the depressed aged subjects. A quasi-experimental method with pre-test and post-test was used. Statistical society of research consisted of the total depressed aged subjects of an aged house (Mehr aged house, Karaj city, Alborze province, Iran).The subjects were divided into two equal groups (12 experimental group and 12 control group) and they responded the lifestyle questionnaire. Then, the percentages of the white blood cells were measured using the flowcytometry method. The experimental group received 14 sessions of the spiritual intervention, then lifestyle and the percentages of the white blood cells were measured. The results showed that there was a significant difference between the experimental and control groups after the intervention on the lifestyle (health, disease prevention, mental health, spiritual health and social health) and the percentages of the white blood cells (neutrophils, lymphocytes, monocytes) (P≤0.05).Thus, spirituality, as a protective factor can promote the health of aged subjects, due to improvement of lifestyle and higher percentages of the white blood cells.
