Melatonin in Alzheimer's Disease: Effect on Disease Progression and Epileptiform Activity.

This is a long-term, prospective, observational study to investigate and compare the levels and rhythm of melatonin in patients with AD dementia, mild cognitive impairment due to AD and healthy volunteers. The investigators would like to validate the use of salivary and urine melatonin measurements as an alternative for blood/CSF melatonin. Furthermore, the investigators would like to assess the effects of melatonin levels on cognition by correlating the levels and changes on cognitive tasks over a two year time frame. The investigators will also investigate whether these effects could be due to its anticonvulsive properties.