02.Causes and symptoms
There are 1500 new cases of dementia diagnosed in Australia each week, and it’s predicted that by 2050 there will be almost one million Australians with the condition - and 10 times as many family members and friends suffering indirectly from its effects.
While there’s no known cure, research shows that cognitive decline in later life is influenced by factors such as high blood pressure, heart disease and high cholesterol, exercise, diet, cognitive activity, mood and sleep. Modifying these factors may protect against the onset of dementia.
Age is also a well-established risk factor for Alzheimer’s disease. A quarter of people aged over 85 have dementia, but it’s now thought that degenerative changes in the brain can start occurring 10, 15 or even 20 years before outward symptoms first appear. Up to 40% of adults over 60 years of age without observable dementia or cognitive decline show signs of Alzheimer’s in their brains when they die.
Late-onset depression – depression that first starts in your 50s – may also be a red flag for brain changes, which can lead to further cognitive decline. To reduce your risk of developing dementia, stay healthy, active and social, and challenge your brain with new activities, especially from your 40s.
The genetic question
Most cases of dementia are not inherited. Direct inheritance or familial Alzheimer’s disease – where a child inherits a mutated gene from a parent (see left) – isn’t common in Australia. However, it means Alzheimer’s disease will develop, usually in the person’s 40s or 50s.
Most people with dementia are affected by sporadic Alzheimer’s disease, which can affect adults of any age (but usually those aged over 65) who may or may not have a family history of the disease. Sporadic late-onset Alzheimer’s disease doesn’t appear to pass directly from one generation to the next, but is associated with the presence of the ApoE14 gene, which can be inherited. This gene is carried by 25% of Australians; although there is an increased risk for these people, about half of ApoE14 carriers who live to 85 years old won’t develop Alzheimer’s disease
Some changes in the ability to think are a normal part of the aging process, but dementia is not part of this. Most healthy adults over 65 experience some decline in cognition such as visual and verbal memory, immediate memory or the ability to name objects and control and maintain attention. On the plus side, vocabulary and verbal reasoning can remain unchanged or even improve during the normal ageing process. Those suffering dementia usually have problems that affect the ability to live independently and perform basic tasks. Stress, lack of quality sleep and depression can also interfere with cognitive function. So while it’s common to occasionally be unable to recall an event or conversation, or to be a bit slow coming up with the word you want, if you frequently forget the names of close friends or family you should speak with your doctor. In the early stages of dementia, changes can be subtle. Sufferers can lose personal insight so they don’t detect changes in their own behaviours. Often, family or friends identify changes first and flag the problem with a doctor.
If any of the following ring true – in yourself or those close to you – speak with your GP:
- Consistently can’t recall the names of close friends or family
- Frequently getting lost in familiar places
- Repetitive questioning and confusion
- Odd or inappropriate behaviours
- Repeated falls or loss of balance
- Personality changes
- Forgetting recent events – even major world events such as a natural disaster
- Decline in planning and organisation
- Changes in diet or eating habits
- Changes in hygiene
- Increased apathy and withdrawal
- Changes in language abilities - previously familiar words mean nothing