Parkinson's disease is an age-related degenerative disorder of certain brain cells and brain tissues. It mainly affects movements of the body,including dementia, may also occur. It is not considered a hereditary disease, although a genetic link has been identified in a small number of families. Depression,personality, anxiety, and behavioral changes, sleep disturbances, and sexual problems are commonly associated with This disease. In many cases, Parkinson's disease does not affect any person's ability to think, reason, learn, or remember which is called as cognitive processes. According to one Study based in France, found in 2015 that men are 50 percent more likely to develop Parkinson's disease than women overall, but the risk for women appears to increase with age. In most people, symptoms appear at the age of 60 years or over. However in 5–10 percent of cases they appear earlier. When Parkinson's disease develops before the age of 50 years, this is called "early onset" Parkinson's disease.