It may be further divided as nonamnestic single- or multiple-domain MCI, and these individuals are believed to be more likely to convert to other dementias (for example, dementia with Lewy bodies).The International Classification of Diseases classifies MCI as a "mental and behavioural disorder." Causes
Mild cognitive impairment (MCI) may be caused due to alteration in the brain triggered during early stages of Alzheimers disease or other forms of dementia. Exact causes of MCI are unknown. It is controversial whether MCI even should be identified as a disorder.Risk factors of both dementia and MCI are considered to be the same: these are aging, genetic (heredity) cause of Alzheimers or other dementia, and cardiovascular disease.Individuals with MCI have increased oxidative damage in their nuclear and mitochondrial brain DNA. Diagnosis
The diagnosis of MCI requires considerable clinical judgement, and as such a comprehensive clinical assessment including clinical observation, neuroimaging, blood tests and neuropsychological testing are best in order to rule out an alternate diagnosis. MCI is diagnosed when there is:
Evidence of memory impairment
Preservation of general cognitive and functional abilities
Absence of diagnosed dementia

Neuropathology
Although amnestic MCI patients may not meet criteria for Alzheimers disease, patients may be in a transitional stage of evolving Alzheimers disease.Magnetic resonance imaging can observe deterioration, including progressive loss of gray matter in the brain, from mild cognitive impairment to full-blown Alzheimer disease. A technique known as PiB PET imaging is used to show the sites and shapes of beta amyloid deposits in living subjects using a 11C tracer that binds selectively to such deposits.
Due to the lack of evidence supporting the efficacy of cholinesterase inhibitors in individuals with MCI, the AAN guideline stated that clinicians who choose to prescribe them for the treatment of MCI must inform patients about the lack of evidence supporting this therapy. The guideline also indicated that clinicians should recommend that individuals with MCI engage in regular physical exercise for cognitive symptomatic benefits; clinicians may also recommend cognitive training, which appears to provide some symptomatic benefit in certain cognitive measures.As MCI may represent a prodromal state to clinical Alzheimers disease, treatments proposed for Alzheimers disease, such as antioxidants and cholinesterase inhibitors, could potentially be useful; however, as of January 2018, there is no evidence to support the efficacy of cholinesterase inhibitors for the treatment of mild cognitive impairment. Two drugs used to treat Alzheimers disease have been assessed for their ability to treat MCI or prevent progression to full Alzheimers disease. Rivastigmine failed to stop or slow progression to Alzheimers disease or to improve cognitive function for individuals with mild cognitive impairment;  donepezil showed only minor, short-term benefits and was associated with significant side effects. Intervention
Current evidence suggests that cognition-based interventions do improve mental performance (i.e. memory, executive function, attention, and speed) in older adults and people with mild cognitive impairment. Especially, immediate and delayed verbal recall resulted in higher performance gains from memory training.