Alzheimer's disease (AD) is the most common cause of dementia worldwide. The etiology is multifactorial, and pathophysiology of the disease is complex. Data indicate an exponential rise in the number of cases of AD, emphasizing the need for developing an effective treatment. AD also imposes tremendous emotional and financial burden to the patient's family and community. The disease has been studied over a century, but acetylcholinesterase inhibitors and memantine are the only drugs currently approved for its management. These drugs provide symptomatic improvement alone but do less to modify the disease process. The current thinking and future research directions in Alzheimer disease (AD), it is essential to examine the breadth of research into AD. AD was identified as a distinct disease process early in this century and research into its etiology and treatment has a short, but active, history. Cholinesterase inhibitors work by slowing down the process that breaks down a key neurotransmitter. Donepezil, galantamine, and rivastigmine are cholinesterase inhibitors and NMDA (N-methyl-D-aspartate) receptor antagonist, which works by regulating the activity of glutamate, an important neurotransmitter in the brain involved in learning and memory. Researchers are looking for new ways to treat Alzheimer's. Current drugs help mask the symptoms of Alzheimer's, but do not treat the underlying disease or delay its progression. A breakthrough Alzheimer's drug would treat the underlying disease and stop or delay the cell damage that eventually leads to the worsening of symptoms.