Young Onset Dementia (YOD): What is it?

Called Young Onset Dementia (YOD), it typically affects 45- to 65-year-olds, though it can also hit people in their early 40s or even late 30s. More aggressive than dementia in the old, it devastates the lives of sufferers at a time when they are still building careers and/or raising children. When hit, they find themselves coping with the diagnosis as well as the emotional and financial fallout. As it progresses, they may not be able to continue working and earning a living.

A relatively new phenomenon in Asia, young onset dementia (YOD) cases have been gradually increasing at the National Neuroscience Institute (NNI) in recent years. Last year, the institute saw 180 new cases, an increase from 100 in the previous year. YOD accounts for a third of all dementia cases seen at NNI.

What causes Young Onset Dementia (YOD)?

According to A/Prof Nagaendran Kandiah, Senior Consultant, Department of Neurology, National Neuroscience Institute, and Assistant Professor, Duke-NUS Graduate Medical School Singapore, there are various reasons for the increase. One could be because of increasing awareness of young onset dementia (YOD) in recent years. Doctors are also diagnosing patients more accurately now with advanced imaging technology. “In the past, these patients would have gone undiagnosed or been misdiagnosed with psychiatric conditions such as depression or pseudo-dementia.” Another reason could be the increasing number of younger people with diabetes, high blood pressure and high cholesterol. “These diseases can lead to strokes which may eventually result in vascular dementia.”

Genetics too can play a part, as about two in five patients have a parent or sibling with the condition. “Previously, when someone had symptoms of young onset dementia (YOD), the problem was usually suppressed. Now, people may notice that their symptoms are similar to those of someone else in the family, and they come forward and get tested,” said Dr Nagaendran.

YOD is often caused by the same brain diseases that afflict older people (see box story) but the progression of brain changes in younger people is usually more rapid, resulting in a faster loss of thinking abilities.

Also, as young people are more active socially and economically, the socio-economic impact on them is greater.

Symptoms of Young Onset Dementia (YOD):

Young onset dementia (YOD) is generally considered when cognitive and behavioural symptoms, which can vary, appear in younger individuals. Sometimes, it becomes apparent at work when patients find it difficult to plan or carry out routine tasks. Symptoms worsen with stress. When this happens, family members may notice changes in their behaviour. They may become less inhibited and display inappropriate behaviour such as poor table manners. Some struggle to find the right words to express themselves and may eventually become mute.

“The loss of language abilities can be frustrating for patients and their families. Over time, they often resort to sign language; but that too, with time, is lost. However, the greater awareness of Young onset dementia (YOD) has resulted in more patients being diagnosed with early symptoms such as word-finding difficulty or usage of wrong words. Previously, these patients would receive a diagnosis only when they were nearly mute.”

How to prevent Young Onset Dementia (YOD):

Dr Nagaendran explained that early diagnosis and treatment are crucial as it is believed that changes in the brain begin 10 to 15 years before symptoms are apparent. Diagnosed early, some cases can be treated and even cured. There are already some drugs available and others are in the final phases of research. One potential drug may offer hope of preventing young onset dementia (YOD) in people with a family history of the disease.

In terms of prevention, one study recommends a preventive measure of having moderate levels of physical exercise at least twice a week, regular mental stimulation, and a diet that includes deep-sea fish, nuts (almonds, walnuts) and berries to slow down progression from mild cognitive impairment to dementia.

Local research on Young Onset Dementia (YOD)

Ongoing genetic research has isolated several important genes associated with young onset dementia (YOD) in Caucasians. Locally, a team led by Dr Nagaendran has started a three year study of young onset dementia (YOD) among Asians, involving more than 300 patients. The first such study in South-east Asia, it is being funded by the National Medical Research Council (NMRC).

“We intend to use advanced neuroimaging techniques and conduct genetic analysis to determine the common genes in the Asian population and look out for other novel genes that could be unique to the Asian population. We will also be inviting family members to participate in the study to identify patterns of inheritance in these families,” Dr Nagaendran said.

Ref. N18