Diagnostic approaches to assessing mild behavioral impairment in patients with mild cognitive impairment

Objective. To assess the prevalence of mild behavioral impairment (MBI ) in elderly individuals with mild cognitive impairment (MCI ), refine diagnostic criteria, and characterize the identified neuropsychiatric symptoms. Material and Methods. Sixty-three individuals over 50 years of age (median 72 [68; 77]) with MCI underwent psychiatric and psychometric assessments using clinical and psychopathological methods and scales. Statistical analysis was conducted to evaluate intergroup differences, ROC-analysis with calculation of the area under the curve (AUC) was performed, and sensitivity, specificity, and accuracy of MBI diagnosis were determined for MBI-C. Results. The prevalence of MBI using only ISTAART research criteria was 65%. An optimal diagnostic cut point for the MBI-C scale with the highest AUC (0.793), at 10 points, was identified. Upon a comprehensive assessment of MBI using criteria and optimal cut point values from the MBI-C scale, the prevalence was 33% (median 16 [14; 20]). Patients with MBI+MCI and MCI only did not significantly differ in MMSE and MoCA test results. Significant intergroup differences were observed in the severity of symptoms such as apathy (p<0.001), depression and anxiety (p<0.001), agitation and impulsivity (p<0.001), social behavioral disturbances (p=0.009), and subsyndromal psychotic symptoms (p<0.001). The most common symptoms were related to impulse control deficits, irritability, agitation, depression, anxiety, and apathy, while less common symptoms were associated with social behavioral disturbances and subsyndromal psychotic symptoms. Conclusion. Novel data on the diagnostic features of MBI in elderly patients with MCI in the Russian-speaking population are presented. An optimal diagnostic cut point for the MBI-C scale in a sample of patients from specialized clinics for comprehensive use with commonly accepted criteria was determined. Further research is needed to adapt and validate the MBI-C scale and provide prognostic evaluation of MBI in the context of MCI progression to dementia.