Dementia and diabetes are the are two major disorders that are found to be linked on Biochemical and Molecular level and it is because that pancreatic cells have molecular similarity with neuronal cells on the transcription and protein levels as well. Both diseases have similar genes in common as their causative agents and dementia is one of the advanced complications of the disease as 50-52% of the population with type 2 diabetes mellitus (T2DM) has greater risk for the development neuronal degeneration and AD (Alzheimers disease) is one of the most common form or cause of the dementia in the individual. In AD it is a common observation that about 80% of the receptors specifically insulin is diminished so the disease is prevailed in the individual. People with diabetes or unable to control blood glucose may have greater uptake of glucose through dietary source which is also one of the reason in the development of the mental disorder. Out of the studies it is concluded that insulin play important role in prevalence of dementia and AD. Impairment in insulin can be one of the leading causes in AD. In these diseases Tau protein and Amyloid beta proteins are significant role players in the formation of plaques in the patients with the dementia or more easily the AD.