Alzheimers disease (AD) is the most common cause of dementia affecting 47% in the population at age over 85.Although there are licensed treatments that can alleviate the symptoms of AD, the efficacious disease-modifying treatments are still missing.The pathophysiological process of AD is believed to begin many years before the diagnosis of dementia and this long preclinical phase would provide opportunity for the intervention.Methods for improving diagnosis are moving forward, but a better consensus is needed to elucidate the link between the pathological cascade of AD and the clinical symptoms.Based on the prevailing scientific evidence to date, a panel of biological and neuroimaging biomarkers that support clinical diagnosis have been developed recently, but further work is needed to understand these better and to establish whether interventions can substantially lower these risks.