Criminal and socially inappropriate behavior occurred more frequently in people who had frontotemporal dementia than Alzheimer's disease, a retrospective review in Sweden found.
Instances of criminal behavior -- including theft, traffic violations, threats, pyromania, vandalism, and stalking -- were found in 42% of patients with pathologically verified frontotemporal lobar degeneration, but only 14.9% of patients with Alzheimer's disease, reported Madeleine Liljegren, MD, PhD, of Lund University, and colleagues.
An expression of non-tau pathology increased the odds for criminal behavior among patients with frontotemporal dementia by a factor of 9, they wrote in .
"Frontotemporal dementia patients also had a higher recurrence of criminal behavior," Liljegren told 51˶. "When studying protein pathology among the frontotemporal dementia patients, there was an overweight of non-tau pathology -- mostly TDP-43 -- among patients who had been exhibiting criminal behavior."
"Criminal and socially inappropriate behaviors could be signs of dementia," Liljegren added. "When previously law-abiding citizens start to behave in an odd way or commit crimes, we suggest that they be screened for neurodegenerative disorders. This could potentially lead to a shorter time from symptom onset to diagnosis and hence proper care in time."
has shown that inappropriate actions and criminal behavior were tied to frontotemporal dementia and Alzheimer's disease. A recent study documented that patients with frontotemporal dementia more frequently than other dementia patients, mostly due to criminal behavior.
"We wanted to study a relatively large cohort of neuropathologically verified Alzheimer's disease and frontotemporal dementia patients who had been followed clinically by specialists in cognitive medicine or geriatric psychiatry during their disease period to see whether we could confirm results from previous studies," Liljegren said. "We also wanted to study potential differences regarding protein pathology and criminal behavior in frontotemporal dementia patients, which to our knowledge had never been done before."
In this study, Liljegren and colleagues looked at patient notes of 220 Swedish people with a postmortem neuropathologic diagnosis of Alzheimer's disease (n=101) or frontotemporal lobar degeneration (n=119) from 1967 to 2017. Overall, 58.2% of patients were female. The median age at disease onset was 63; the median age at death was 72.
Instances of criminal behavior were found in 15 of the 101 Alzheimer's patients (14.9%) and 50 of the 119 frontotemporal dementia patients (42.0%; P<0.001). Instances of socially inappropriate behavior were found in 57 patients (56.4%) with Alzheimer's and 89 (74.8%) with frontotemporal dementia (P=0.004). In patients with frontotemporal pathology who exhibited criminal behavior, the expression of tau pathology (n=6) was less common than the expression of non-tau pathologies (n=44).
Recurrence of criminal behavior was significantly higher in the frontotemporal dementia group (89.0%) than in the Alzheimer's group (53.3%; P=0.04). "This finding is not surprising because patients with frontotemporal dementia have often experienced damage to their frontal lobes, where (among other functions) is located," the researchers noted. Several patients with frontotemporal dementia said they knew their criminal behavior was inappropriate.
"Prospective studies, including imaging, with neuropathological follow-up is required," Liljegren said. "We recommend that research include judicial outcomes for these patients, since frontotemporal dementia patients can sometimes verbalize that their actions are wrong but proceed with criminal behavior. This is especially problematic when frontotemporal patients are facing criminal charges."
This study had several limitations, the authors noted. Findings were based on patient records; the researchers did not have access to criminal records or extensive details about criminal behavior. It's possible the number of criminal incidents was higher but patients or families did not report them. In addition, the researchers' interpretation of whether patient behavior was criminal or socially inappropriate was based on what is legal or deemed appropriate in Sweden.
Disclosures
Liljegren disclosed no relevant relationships with industry. A co-author disclosed support from the National Institute on Aging, University of California San Francisco/Quest Diagnostics Dementia Pathway Collaboration, and the National Institute of Neurological Disorders and Stroke.
Primary Source
JAMA Network Open
Liljegren M, et al "Association of neuropathologically confirmed frontotemporal dementia and Alzheimer disease with criminal and socially inappropriate behavior in a Swedish cohort" JAMA Network Open 2019; DOI: 10.1001/jamanetworkopen.2019.0261.