Dementia is a growing public health concern because of the lack of effective curative treatment options and a rising global prevalence. Alzheimer's disease (AD) is the most common type of dementia, affecting 60%-70% of all patients with dementia. The main pathological features of Alzheimer's dementia are neurofibrillary tangles and senile plaques caused by progressive deposition of β-amyloid in the brain, but its underlying pathological basis is unclear. In common late onset AD sporadic forms (95% of all AD cases), a major genetic risk factor is the apolipoproteinE-ɛ4 (ApoE-ɛ4) alleles, and other genetic determinants have also been proposed to play causative role. This review focuses on biomarkers and subsequent changes in continuous measurement of cognitive and functional abilities in patients with mild cognitive impairment (MCI) and AD that aim to achieve a higher diagnostic accuracy for AD along with clinical assessment, neuropsychological testing and neuroimaging.