Dementia isn’t one specific disease, but a way of describing a set of symptoms that are caused by disorders affecting the brain. While Alzheimer’s disease is the most common form of dementia, there are others, including vascular dementia, Creutzfeldt-Jakob disease and dementia with Lewy bodies.
Both short- and long-term memory loss are primary symptoms of dementia, but almost 40 per cent of people over 65 experience some form of mild memory loss, most of whom don’t develop dementia, indicating that it isn’t the only symptom. Other signs include changes in mood or behaviour and challenges with thinking, problem-solving or language that interfere with one’s ability to perform everyday activities.
As for why most people living with dementia are over the age of 65, there are a host of reasons, says Natalie Phillips, a Department of Psychology professor and Concordia Research Chair in Sensory-Cognitive Health in Aging and Dementia.
“It could be years of subtle vascular changes or inflammatory processes in the brain that just take time to manifest themselves,” she says. “And then the natural mechanisms that the brain has to combat these kinds of insults start to weaken as people get older. You also start to develop other health conditions in later age that can amplify the problem.”