Introduction: Literature on criminal behavior preceding a neurodegenerative disease diagnosis is insufficient. Some studies suggest increased crime rates among patients with frontotemporal dementia (FTD).
Methods: Patients with neurodegenerative diseases were gathered from Kuopio and Oulu University Hospitals and compared with nonselective general population data from Statistics Finland (N = 24,144). Clinical data were linked to the Finnish national register of police-reported crimes.
Results: In total, 2424 participants with neurodegenerative diseases were included. Overall crime rates were notably higher among patients with FTD during the year before the diagnosis (9.4% for FTD, 6.3% for controls, p = 0.019). There was a significant drop in the criminal rates of FTD patients 3 years after the diagnosis (4.7% in the FTD, 12.3% in controls, p < 0.001).
Discussion: Criminal behavior is overrepresented in patients with FTD before the diagnosis. Criminal behavior manifesting in previously law-abiding individuals in late adulthood should be considered a potential early symptom of a neurodegenerative disease.
Keywords: behavioral symptoms; criminal behavior; criminality; dementia; neurodegeneration.
© 2025 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.