ABSTRACT
Alzheimer’s disease (AD) is a progressive neurodegenerative disease that is characterized by a decline in memory and cognition, resulting in an inability of an individual to function alone. The trend of increasing elderly populations due to increased life expectancy has surged the Alzheimer’s population globally, i.e., around 50 million. The etiopathology and neurochemistry of AD are complex and incompletely understood to date. However, it has been reported that age, gender, race, environmental factors, air pollution, infection, genetics, comorbidities (cardiovascular, obesity, and diabetes), and lifestyle are potential risk factors associated with Alzheimer’s. Based on the cut-off of age 65, AD is categorized as early or late onset. The neuropathology of Alzheimer’s has been linked with the formation and deposition of β-amyloid plaque and neurofibrillary tangles; this deposition results in immunological reactions and amyloid angiopathy. Further, altered neurochemistry is one of the factors associated with AD pathogenesis. The altered concentration of neurotransmitters such as acetylcholine, dopamine, serotonin, nor-adrenaline, glutamate, and GABA in the brain and any pathological changes in their respective neurons and corresponding receptors contribute to the development of psychiatric illnesses, including AD. The pathogenesis of AD makes it difficult to treat, resulting in poor prognosis of patients, which corresponds with a huge disease burden, poor quality of life, and high economic burden.
