Background: Neuropsychiatric symptoms (NPS) have been recognized as risk factors for conversion to dementia in patients with mild cognitive impairment (MCI). Early detection of NPS may allow for possible interventions in such patients. The present study used mild behavioural impairment to explore the role of NPS in a wide range of patients, from those who are cognitively intact to those with dementia.
Methods: A total of 234 patients with mild cognitive impairment were followed up for up to 3 years in a Japanese cohort study. Longitudinal data from patients who developed dementia during the study and those who did not were statistically analyzed.
Results: Cox regression analysis revealed that only abnormal perception and thought was significant in terms of dementia conversion. Moreover, mixed-effects models indicated that baseline mild behavioural impairment symptoms did not affect cognitive trajectories such as changes in Mini-Mental State Examination or Alzheimer's Disease Assessment Scale-cognitive subscale scores.
Conclusion: We conclude that only abnormal perception and thought content were risk factors for dementia and that NPS may not lead to deterioration of cognitive function in patients with mild cognitive impairment.
Keywords: Alzheimer's disease; behavioural and psychological symptoms of dementia; dementia; mild behavioural impairment; mild cognitive impairment; neuropsychiatric symptoms.
© 2019 Japanese Psychogeriatric Society.