Neuropsychiatric symptoms and social cognition in frontotemporal dementia and Alzheimer’s disease

Neuropsychiatric symptoms (NPS) are common in dementia and may hinder differential diagnosis between behavioral variant frontotemporal dementia (bvFTD) and Alzheimer’s disease (AD). Despite investigations of NPS and social cognition, particularly Theory of Mind (ToM) and emotion recognition, their precise, differential impact on social cognition in bvFTD versus AD remains less characterized. Objective: This study examined NPS in bvFTD and their association with social cognition, comparing results to AD. Methods: Patients with bvFTD (n=13) and AD (n=18) were assessed using neuropsychiatric and cognitive batteries measuring depression, anxiety, mania, and psychosis. Social cognition was evaluated with the Mini-Social and Emotional Assessment (mini-SEA), including the Faux-Pas test (ToM) and the Facial Emotion Recognition Test (FERT). Results: The groups did not differ in sex, education, or disease duration. Compared to AD, bvFTD patients had higher manic symptoms (p<0.001) and schizophrenia spectrum symptoms, particularly in negative (p<0.001) and resistance/hostility (p=0.034) symptoms. In bvFTD, depressive (p=0.020) and anxious (p=0.045) symptoms positively correlated with the Faux-Pas test, while positive psychotic symptoms correlated negatively (p=0.005). In AD, obsessive-compulsive (p=0.013) and disorganized psychotic symptoms (p=0.009) negatively correlated with the Faux-Pas test, while manic symptoms negatively correlated with the FERT (p=0.033). Conclusion: bvFTD patients displayed more schizophrenic and manic symptoms than AD, with NPS impacting social cognition differently in each condition.