BDNF and early-onset autosomal dominant Alzheimer disease: According to a study undertaken by Weinstein et al. relating to the connection between the level of BDNF in the serum and the risk for developing dementia, a ten-year follow up of the effects of BDNF in a particular community showed that, out of 2131 participants, 140 participants had a positive risk of dementia and 117 of them were at positive risk of Alzheimer’s disease [125].