US-Based Study Measures Criminal Behaviour In People With Dementia

Researchers from the US, Australia and Sweden have analysed levels of criminal behaviour in people with different forms of dementia, finding that those with frontotemporal dementia are most likely to behave antisocially or break the law, and those with Alzheimer’s disease least likely.

Dementia is a term used to describe a collection of symptoms including memory loss, confusion, behaviour change and communication problems. The different diseases that cause dementia can lead to a diverse range of symptoms. While memory loss and confusion tend to be predominant symptoms in Alzheimer’s, people with frontotemporal dementia tend to experience marked changes in personality and behaviour. Frontotemporal dementia (FTD) also comes in different forms, with behavioural variant (bvFTD) mainly affecting behaviour, and semantic variant of primary progressive aphasia causing marked problems with language and recognising words and objects.

The researchers carried out a retrospective review of medical records of 2,397 people with dementia who visited the University of California Memory and Aging Centre between 1999 and 2012. These included people with Alzheimer’s disease, bvFTD, semantic variant of primary progressive aphasia and Huntington disease. Of all those studied, 8.5% had carried out criminal behaviour since developing their illness. The team found that those most likely to have carried out criminal behaviour were those with bvFTD (37.4% of those studied). The most common criminal behaviours reported in this group were theft, traffic violations, sexual advances, trespassing and public urination.

The team reported that 27% of people studied with semantic variation of primary progressive aphasia had a record of criminal behaviour, 20% of those with Huntington disease and 7.7% of people with Alzheimer’s disease. For those with Alzheimer’s, traffic violations were the most common.

Dr Laura Phipps of Alzheimer’s Research UK, the UK’s leading dementia research charity, said:

“People often associate dementia with memory problems but many people can also experience changes in behaviour and personality. Sadly, damage to areas of the brain controlling behaviour and judgement can cause people to make decisions about their actions that may normally be seen as inappropriate, leading them to break the law. People with frontotemporal dementia tend to experience severe changes in behaviour and a lack of inhibition and this US study highlights that they are most likely to carry out antisocial or criminal activity as a result.

“It’s important to recognise that at some stages in their condition, people with dementia are likely to need help and support in the community. Behavioural symptoms can bring an additional challenge for people with dementia and those around them. Developing approaches to help people with dementia manage their symptoms, including behaviour change, is important to support them, their carers and families in maintaining a good quality of life.”