Clinical applicability of the BT2-NPS for assessing neuropsychiatric symptoms across the Alzheimer’s disease continuum

OBJECTIVE: This study aimed to examine the clinical applicability of the Barcelona-2 Test Neuropsychiatric Symptomatology Scale (BT2-NPS) in a Spanish population comprising healthy controls (HC), individuals with single-domain amnestic mild cognitive impairment (aMCI), and individuals with Alzheimer's disease (AD). Specifically, the study sought to characterize the distinct trajectories of neuropsychiatric symptoms (Behavioral and Psychological Symptoms of Dementia BPSD) across the cognitive continuum and evaluate the scale's diagnostic utility. METHOD: A total of 37 HC, 31 aMCI, and 76 AD participants, aged 60-85 years, were assessed using the BT2-NPS. Quade's test (controlling for age and education) was used to examine the differences in BT2-NPS scores across diagnostic groups and Global Deterioration Scale (GDS) stages. Symptom progression was analyzed descriptively to identify patterns, and partial convergent validity was explored using the Goldberg Anxiety and Depression Scale (GADS). RESULTS: The BT2-NPS Total score significantly differentiated between diagnostic groups and GDS stages. Three distinct symptom patterns emerged: a "Severity-Dependent" Pattern (e.g., apathy, insight loss) increasing linearly with severity; an "Inverted-U Pattern" (e.g., anxiety, depression) peaking in prodromal stages before declining; and a "Late-Emergence Pattern" (e.g., hallucinations) appearing only in advanced stages. No gender differences were observed. Correlations with self-reported GADS were weak. CONCLUSION: Findings support the BT2-NPS as a clinically meaningful tool for staging BPSD in older adults. Crucially, the study demonstrates that affective symptoms may decline in later stages not due to clinical remission, but due to the progression of apathy and loss of insight. The scale captures this complex behavioral landscape, contributing to more personalized and compassionate care approaches.