Specific cognitive impairment predicts the neuropsychiatric symptoms in patient with mild cognitive impairment.

Background: Neuropsychiatric symptoms (NPS) are common in mild cognitive impairment (MCI). However, knowledge is limited about the relationship of NPS, clinical factors, and cognition in MCI.

Methods: A total of 1099 dementia, 1323 MCI and 377 cognitively normal (CN) were selected from the Tongji Cohort Study of Aging. All participants underwent comprehensive clinical and neuropsychological assessment. NPS were evaluated by the Neuropsychiatric Inventory Questionnaire (NPI-Q). Logistic regression analyses were conducted to investigate the relationship between clinical factors, cognition and NPS.

Results: The NPS presented in 56.39% of MCI participants, and the NPI-Q scores of MCI was intermediate between CN and dementia. The most common NPS in MCI were depression (30.76%), anxiety (25.09%), apathy (19.43%), and irritability (12.02%). MCI patients with NPS showed worse performance in global, memory, language, and attention than those without NPS. Additionally, Logistic regression analyses revealed that MCI patients with ischemic heart disease (OR = 1.41; 95%CI 1.050-1.897; P = 0.022) were more likely to have NPS, but MCI patients with increased memory domain Z score (OR = 0.847, 95%CI = 0.720-0.996, p = 0.044), and language domain Z score (OR = 0.801, 95%CI = 0.682-0.941, p = 0.007) were less likely to have NPS.

Conclusions: Neuropsychiatric symptoms occur commonly in MCI participants, and are mainly related to defect of language and memory function. A better understanding of the relationship between specific cognition and NPS may alert clinicians to pay close attention to the NPS in MCI patient, which may need early intervention.