The definition of clinical mild cognitive impairment remains variable. In my view it generally refers to a condition where day-to-day memory and/or ability in other areas of cognitive or executive function has declined to a point, where compared to accustomed level of mental function it now stands out as a downward shift that is somewhat interfering and bothersome at times and therefore of concern but not derailing of accustomed day-to-day activities and not meeting diagnostic criteria for dementia. It is often noticed in middle age and feels like an acceleration or compression of the more subtle loss of mental efficiency with aging that the individual has experienced up until that point—and as if some threshold has been passed so that there is now some significant qualitative change. It may be the expression of ware-and-tear on brain tissue caused by a number of converging factors, finally reaching a degree of impact on the mind that is considered quite noticeable in day-to-day function.

MCI can be diagnosed by neuropsychological assessment. Treatment approaches that may possibly be of benefit to those showing MCI may be offered by naturopaths (such as the application of chelating compounds that help remove of heavy metals from the body), physicians specialized in anti-aging medicine, and others who offer neurofeedback, cognitive exercises or meditative techniques.