In a third model of Alzheimer’s disease, the TgCRND8 model, leptin has been reported to be effective in ameliorating pathology and cognition (reviewed in [85]), and leptin and lithium appear to share some molecular targets, such as GSK-3beta and PI-3 kinase [86], and interrelationships. Here, LEP is linked to early-onset autosomal dominant Alzheimer disease.