Abstract Background The use of cannabidiol (CBD) has grown rapidly over the last few years. CBD has been purported to work on a range of conditions, including anxiety, pain, and psychosis. There has been recent interest in CBD as a treatment for age-related cognitive disorders due to its antioxidant and anti-inflammatory properties. Method Here, we tested the effects of chronic CBD administration on learning and memory in the SAMP8 mouse model of Alzheimer’s disease. SAMP8 mice develop an age-related impairment in learning and memory which corresponds to an increase in amyloid-β (Aβ), hyperphosphorylated tau, oxidative stress, impaired efflux of Aβ across the blood-brain barrier...