The Coenzyme nicotinamide adenine dinucleotide (NADH) has been used as medication in 17 patients suffering from dementia of the Alzheimer type in an open label trial. In all patients evaluated so far, an improvement in their cognitive dysfunction was observed. Based on the minimental state examination, the minimum improvement was 6 points and the maximum improvement 14 points with a mean value of 8.35 points. The improvement on the basis of the global deterioration scale (GDS) was a minimum of 1 point and a maximum of 2 points with a mean value of 1.82. The duration of therapy was between 8 and 12 weeks. No side effects or adverse effects have been reported from the patients or their caregivers during the observation period which is, in some patients, more than a year. This open label trial represents a pilot study from which no definitive conclusion can be drawn. A double-blind placebo controlled study is necessary to demonstrate the clinical efficacy of NADH. The planning and the fulfillment of all requirements for such a study are in progress.