Patients with frontotemporal dementia are more likely to manifest criminal or socially inappropriate behaviour than those with Alzheimer’s disease, Swedish researchers report.

And those with frontotemporal dementia (FTD) who behave in criminal ways are nine times less likely to have tau protein pathology than those with the dementia who are law-abiding, the research shows.

In a review of medical records of 220 deceased patients, 119 with a post-mortem diagnosis of FTD and 101 with post-mortem confirmed Alzheimer’s disease were compared for reports of criminal or socially inappropriate behaviour.

There were 50 criminal incidents (42%) among the FTD group, compared with 15 in the Alzheimer’s group (15%), a 3.5-fold increase in odds after adjusting for age and sex.