Background Delusional misidentification syndromes (DMS) involve erroneous identification of people, objects or places. They have been described in several psychiatric and neurological diseases, particularly in cognitive disorders and dementia. We report an unusual form of DMS in patients with dementia: the belief that individuals depicted in photographs or static images are alive. Methods In this retrospective analysis, four patients followed in our memory clinic between March 2009 and June 2025 were selected for having developed, during follow-up, the belief that individuals depicted in two-dimensional representations were alive, as reported by themselves or caregivers. A standardised neuropsychological battery assessed the main cognitive domains. Final diagnoses were established during multidisciplinary consensus meetings based on neuropsychological assessments, brain MRI, 18F-FDG-PET, DaT-scan results (when available) and cerebrospinal fluid (CSF) biomarkers. Clinical data are detailed in this study. Results All four patients exhibited core delusions in the context of dementia, with heterogeneous severity, symptom duration and treatment response, but all showed marked emotional-behavioural involvement and functional decline. Neuroimaging demonstrated widespread frontoparietotemporal hypometabolism with consistent right-hemispheric involvement; two patients had predominant left-sided hypometabolism without clinical differences. CSF biomarkers indicated Alzheimer’s pathology in all cases, and probable dementia with Lewy bodies was diagnosed in two patients based on core clinical features, including a positive DaT-scan in one of them. Conclusions We describe a previously unreported DMS variant—‘animated picture syndrome’—characterised by the belief that individuals depicted in photographs or static images are alive, sometimes leading to behaviours such as reluctance to leave home or preparing food for them. In our series, this syndrome emerged in the context of neurodegenerative disease and coincided with cognitive and functional decline. Its recognition may help identify clinical deterioration and prompt appropriate aetiological work-up, caregiver education and therapeutic interventions. Further studies should clarify its prevalence, mechanisms and relationship with other DMS variants.
Bertrand et al. (Thu,) studied this question.
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