Chinanews, Beijing, March 14 – Currently there are some 1.7 million people suffering from Parkinson's disease in China (about 50% in the world), and an in-depth research on depression caused by Parkinson's disease has been launched in 7 Chinese cities.“Most people are not aware of the connection between depression and Parkinson's disease. However, depression might be one of the earliest signs of the disease, even earlier than trembling,” said Lu Chuanzhen, an expert on neurology from Huashan Hospital of Fudan University in Shanghai. “In fact, depression is a great hazard, as it accelerates the process of dementia, and puts a heavy burden on both patients and their families. ”With the aging of population in China, doctors must be prepared to treat increasing number of Parkinson's disease patients. It is believed that this 6-month research will find all the emotional symptoms of the Parkinson's disease and their causes.Chinese doctors have paid much less attention to the “hidden pains” caused by Parkinson's disease than their counterparts in developed countries.The result of the research will be released by the end of 2007, when it will offer timely aid to both patients and doctors, as well as to the modification of public health policies in China.