Neurological disorders (Alzheimer’s, Parkinson’s, dementia and other neurodegenerative illnesses, epilepsy, multiple sclerosis and strokes), psychiatric disorders (anxiety, depression, addiction, schizophrenia, autism, obsessive-compulsive disorder) and defects of the sense organs (visual or hearing deficiencies) affect many patients and their families. The scale and frequency of these problems have gradually become known as our knowledge of their symptoms and etiology has become more detailed.
Neurodegenerative illnesses are dominant among neurological disorders because of their increasing frequency and severity caused by the aging of the population. In France, more than 860,000 people suffer from Alzheimer’s and 100,000 from Parkinson’s. Other diseases have a high incidence or prevalence, including strokes (150,000 new cases a year), epilepsy (500,000 patients) or multiple sclerosis (60,000 cases). Youngsters are affected by such developmental problems as dyslexia, attention disorders, dyspraxia or dyscalculia (6% of children suffer from dyslexia or related disorders). Hundreds of patients also suffer from rare diseases like fragile X syndrome, Tourette syndrome or Friedreich’s ataxia.
Psychiatric disorders are even more common, affecting 1 in 4 adults, or 27% of the population: 10 million with depression, 600,000 with bipolar disorder, 600,000 with schizophrenia, 4 million suffering from anxiety, 60,000 with autism and 1.5 million addicts, to mention but the most frequent problems. Lastly, 4 million people suffer from hearing deficiencies and 2 million from retina-related visual problems, particularly age-related macular degeneration (ARMD). A specific initiative has been implemented for some of these disorders, such as the Plan Alzheimer et maladies apparentées (Plan for Alzheimer's and related diseases), announced by the French President in 2007 and in force since 2008.
The economic stakes depend on how common these disorders are, on the associated disability and hospital expenditure incurred. Accordingly, the cost of brain diseases is €387 billion in Europe, 60% of which arises from mental diseases, which are the second cause of work stoppage and number one cause of disablement in France. The cost of hearing deficiencies exceeds €100 billion due to the necessary hearing aids and specialist education. Disorders of the nervous system alone account for a third of the human cost of all diseases in Europe.