Mild cognitive impairment (MCI) is a recent diagnostic category that describes a decrease in cognitive ability that is less severe than that seen in dementia. MCI is associated with an increased risk of dementia, but many individuals diagnosed with MCI revert to their normal cognitive function. It is important for clinicians and researchers to identify factors that indicate a good prognosis for recovery from MCI, both for diagnostic purposes and to develop interventions that may be used to prevent or delay cognitive decline. A study recently published in the open-access journal PLOS ONE identified factors associated with reversion to normal cognition in a sample of community-dwelling older adults.
The study included 320 community-dwelling older adults in the Sydney, Australia, area who were diagnosed with MCI. Participants were given a battery of neurological and cognitive assessments, personality tests, and a physical examination, and were surveyed on demographic, lifestyle, and health factors. About half of the participants also consented to an MRI scan. Participants were given a follow-up diagnostic assessment for MCI two years after their initial assessments; 86 of the initial participants were lost to follow-up because they were deceased, declined to participate, or were otherwise unable to be diagnosed.
Sixty-six of the 234 participants assessed at the two-year follow-up had reverted to normal cognitive ability, while 11 had developed dementia. The investigators looked for factors that were associated with reversion, and found that participants who had higher initial cognitive ability, who had the personality trait of being open to experience, who had improved their diastolic blood pressure, and who had better vision or smelling acuity were all more likely to return to normal cognitive ability. Future research will determine whether these findings can be replicated in other studies, which might lead to better models for predicting and preventing cognitive decline.