Homocysteine, folate and vitamin B12 in neuropsychiatric diseases: review and treatment recommendations.

In Europe, neuropsychiatric diseases currently make up approximately a third of the total burden of disease. In 2004, 27% of the overall population was affected by at least one of the most frequent neuropsychiatric diseases such as Alzheimer's dementia, Parkinson's disease, stroke or depression. The annual costs of care exceed those of cancer, cardiovascular conditions and diabetes.