The etiology and treatment of disease is controlled by culture. They reflect the belief system of a culture and are inherently tied to it. Religion and medicine are closely associated with each other in non-western cultures and disease is believed to be caused by natural or supernatural means. As science is an outgrowth of religion, it too is tied to medicine in the west, almost exclusively. Anthropologists have studied non-western cultures throughout the world and have identified six primary disease theories that are prevalent. These include natural causes, imitative and contagious magic, object caused disease, soul-loss, spirit-intrusion, and breach of taboo. The cause of disease western culture is exclusively natural.
Treatment of disease is determined by its cause. Ethnomedicine may treat headaches with sucking, as the cause is an object intrusion created by magic. Western medicine may treat the same headache with synthetic anti-inflammatory drugs like naproxen, identified by its chemical signature C14H14O3. Epilepsy may be treated in non-western society by performing a ceremony to find and retrieve a lost soul because it is caused by soul-loss, while in the west it is treated with anti-seizure drugs which inhibit the wild firing of neural impulses.
Because of the belief in supernatural causation of disease in ethnomedicine, treatment is very often of a spiritual nature. In the west, all causation is natural and treatments are with pharmaceuticals. In some cases the supernatural treatments are more effective than western treatment for the same disease, as in the case of mental illness. Cure rates using ethnomedicine are more than double those in the west. Because of the tenant of science that requires proof before belief, there are no supernatural causes of disease. It is most interesting to note, though, how effective retrieval of a soul can be in curing a disease. It is belief (religion) that may hold the key.