The present invention discloses administering steroid hormones to mammals to treat autoimmune related diseases, neurodegenerative diseases or disorders, such as Alzheimers disease, Parkinsons Disease, multiple sclerosis, stroke, ALS Picks disease, prion disease and Huntingtons disease. Most preferably the invention uses estrogens, estranges, estriol or estrogen receptor active agents to prevent or ameliorate clinical symptoms of the diseases and disorders.
