Although violations of laws, such as shoplifting, are considered to be common in frontotemporal dementia (FTD) patients, there have been few studies on this subject and the frequencies and types of such violations have not been clarified. The objective of this study was to conduct a retrospective investigation of FTD patients in the psychiatry departments of multiple institutions to determine the types and frequencies of any law violations and compare them with those of AD patients. All patients were examined between January 2011 and December 2015 at the specialized dementia outpatient clinics of 10 facilities (5 psychiatry departments of university hospitals, 5 psychiatric hospitals). According to diagnostic criteria, 73 behavior variant FTD (bvFTD) patients, 84 semantic variant of primary progressive aphasia (svPPA) patients, and 255 age- and sex-matched AD subjects as the control group were selected. The findings revealed a higher rate of law violations in the bvFTD and svPPA patients before the initial consultation as compared to the AD group (bvFTD: 33%, svPPA: 21%, AD: 6%) and that many patients had been referred due to such violations. Laws had been broken 4 times or 5 or more times in several cases in the FTD group before the initial consultation. Regarding rates for different types of violation, in bvFTD subjects, the highest rate was for theft, followed by nuisance acts and hit and run. In svPPA, theft had the highest rate, followed by ignoring road signs. There was no gender difference in law violations but they were more frequent when the disease was severe at the initial consultation in the FTD group. As the rates of law violations after the initial consultation were lower than before it, interventions were considered to have been effective. These findings may be useful for future prevention as well as to the legal system.
Keywords: Behavioral symptoms; frontotemporal dementia; legal system; violation of laws.