Music therapy is an effective treatment for Alzheimer's disease. It improves social behaviors and reduces agitation. Music therapy is thought to work by altering how patients perceive their environment, making noises seem familiar and lessening fear. It provides structure and allows for interaction. Neuroimaging shows the brains of musicians differ structurally from non-musicians, indicating music can cause anatomical changes. Music affects the production of neurotransmitters, hormones, cytokines and peptides in the body. It has been shown to increase estrogen and testosterone while decreasing cortisol, helping to reduce stress. This may be one mechanism by which music therapy helps cognitive functions in Alzheimer's patients.