Last major update: September 2019 - Please read disclaimer before proceeding

 

What is dementia and how common is it?

Dementia is the gradual decline in a person’s thinking (cognitive) capabilities to the extent that it affects their ability to perform normal everyday activities. Society expects a mild decrease in mental ability in people as they age (although in many people this does not occur) and thus diagnosis of the condition is often delayed. The fact that the death rates from other major diseases has reduced dramatically over the past 40 years has meant that many more people end up living to the age that they develop dementia. (Death rates from both stroke and heart attack have reduced by about 75% over the past 40 years.)

Dementia is a condition that presents mostly in old age with about 5% of people in their 60s, 10% of people in their 70s and about 25% of people in their 80s suffering from the condition. About 1% of 65 year olds and 40% of 90 years olds are affected and, after the age of 65 years a persons risk of developing the disease doubles every five years. In 2018 about 376,000 Australians were affected and this figure is expected to rise to 550,000 by 2030. It is the now the most common cause of death for women and the third most common cause for men and is the second greatest cause of illness in people over the age of 65 years, accounting for 7.8% of illness in this age group.

Early onset dementia, before the age of 50, occurs in 5% of cases.

The prognosis of people with dementia is generally poor. Mental function continually declines until the sufferers are unable to be cared for at home and need nursing home care. Once there they live an average of five till succumbing to death by brain failure. (Presently about 80% of people in high-care residential facilities have significant dementia.)

As we are living increasingly longer lives, many more people are going to be affected by dementia and it is likely that in the near future it will become Australia’s most important health problem and place great pressure on the country’s ‘already stressed’ health budget. However, while our ageing society will increase the number of dementia cases, the risk of individuals getting dementia at a certain age is actually decreasing, probably due to the fact that we are looking after the risk factors for vascular disease better and because we are becoming better educated as a population, both of which help protect against dementia. This means that, while the perentage of eighty years olds who have dementia is decreasing, the fact that more people are reaching eighty means that, in total, there are more eighty year olds with dementia.

Memory changes are the first sign of the development of Alzheimer's Disease. The memory changes that indicate that dementia might be developing include rapidly forgetting new information, repeating questions and disorientation in time. Self-neglect, apathy and poor decision making are also indicators. The Mini Mental State Examination is the cognitive test most used in Australia to diagnose all types of dementia.

How big is the problem?

At present there are thought to be about 400,000 people with dementia in Australia and it costs 14 billion dollars per year; a bit less than 1% of GDP.

Is dementia improving?

There is evidence that the incidence of dementia at any given age is decreasing, probably due to better management of vascular disease risk factors and better nutrition and education. However, these same factors have also led to people livinhg longer and thus more people are getting dementia. They are just getting it a bit later in life. What needs to happen is for the delay in onset to increase furher.

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Types of dementia

There are various causes for dementia but in developed countries such as Australia two main types, Alzheimer’s Disease (65%) and Vascular Dementia (15%), account for about 80% of cases. (Vascular dementia is more common in undeveloped countries.) Both are due the death of brain cells and loss of brain cell connections, called synapses. (Each brain cell has about 10,000 of these connections!!!) The cause of this process in both types of dementia is still very unclear. Interestingly, when looking at the brains of people who had dementia, the majority show changes characteristic of both types. Individual difference in the ability to replace lost brain cells and brain cell connections may play a role in deciding who suffers from dementia.

About 5% of dementia is due to frontotemporal dementia and 5% due to dementia with Lewy bodies. Other diseases associated with dementia include alcohol abuse, Parkinson’s disease, Huntington's disease and brain infections or trauma.

Alzheimer’s Disease

In Alzheimer’s Disease (AD) the loss of brain cells starts in the hippocampus, which is located deep in the lower part of the brain and is responsible for memory. Thus loss of short-term memory is the characteristic feature early on in this disease, causing problems such as loss of important items around the house, being unable to find the way home, ailing to recognise loved ones and forgetting important events.
Later the loss of brain cells spreads to other parts of the brain and a more generalized loss of brain function occurs.

The cause of AD is still very unclear. There are characteristic changes, mainly deposits of a pathological protein called beta amyloid, that occur in the hippocampus and these characteristically begin to occur many years before symptoms occur (up to 30 years).This protein attracts another protein called Tau and together they form fibrous clumps inside brain cells that disturb the brain's message system and neural networks disintergrate.

Inheritance verses environment risk factors: Inheritance is a major factor in only a small number of cases. Only about 1% of cases are very significantly inherited (the familial form) and in these cases the dementia onset is quite early; in their 50s. (It is transmitted in an autosomal dominant pattern which means that the children of sufferers have a 50% chance of developing the condition as well.) In the much more common later onset type, the genetic component is thought to only contribute about 25% of risk. The other 75% is thought to be related to environmental factors.

What causes these deposits is unclear. Recent evidence suggests that disruption of blood supply may be a factor. Risk factors for vasdcular disease are also to some extent risk factors for Alzheimer's disease, including diabetes, smoking, high blood pressure and high blood cholesterol. Family history can also be a factor and is more likely when Alzheimer's comes on at an early age. Education and mental stimulation may reduce risk. (See below.)

About 30% of Alzheimer's is caused by known environmental risk factors that can be modified. (Discussed later.)

Vascular dementia (VaD)

The cause of VaD is thought to be multiple disruptions (blockages or ruptures) of very small blood vessels in the brain. These disruptions may be due to vessel blockages, resulting in small areas of ‘brain death due to lack of oxygen, or more commonly, small vessel ruptures which result in small brain haemorrhages (microhaemorrhages) that also cause cell death. The risk factors for the disease are similar to the risk factors for other vascular diseases, such as heart attacks; that is, high blood pressure, smoking, diabetes, high cholesterol, obesity and physical inactivity. Atrial fibrillation, a relatively common abnormal heart rhythm, can cause small clots to travel from the heart (where they form) to other parts of the body, including the brain where they can cause both strokes and dementia. (People with atrial fibrillation are usually prescribed life-long anti-clotting treatment to help prevent such occurrences.) A healthy heart and a healthy brain go hand-in-hand.

Vascular dementia (VaD) occurs in about 2% of people after they have a stroke and interestingly it usually comes on gradually over the following year. Also interestingly, the severity and location of the stroke does not seem to influence the severity dementia or the type of symptoms that initially occur.

Thus, irrespective of the location of the stroke, VaD mainly affects connections to and within the frontal lobes of the brain. The frontal lobes are concerned with complex thinking and behaviour and thus the person initially suffers from problems with complex tasks such as problem solving and may act inappropriately, such as crying in unusual situations or becoming inappropriately angry.

Pressure waves in the brain due to artery wall stiffness and high blood pressure in midlife - A new hypothesis on the cause of dementia

Traditionally vascular disease is thought to influence dementia by causing narrowing of the arteries supplying the brain with blood and thus reducing nutrient / oxygen supply to brain tissue.

However, another recently proposed theory regarding the cause of dementia is that the presence of a high level of stiffness in the arteries supplying the brain sets up larger pressure waves through the brain tissue and this causes damage to brain cells that causes them to leak substances and this eventually leads dementia. This process may involve the oxidation and inflammation of tissue surrounding the damaged cells and the leakage of numerous proteins such as amyloid. Whether or not proteins like amyloid that are found in the brains of people with Alzheimer's disease are the cause of dementia is a debated point and it may well be that the presenece of these proteins are more markers of a complicated damaging process that causes dementia rather than the actual cause of the dementia.

A continuing study, initiated in 2003, of 3,200 well people aged 60 years showed that the most inportant risk factor for Alzheimer's disease in this group is the intensity of the blood pressure pulse to the brain. This pulse wave intensity. This is measured by a simple scan that assesses the wave intensity in the carotid arteries (the main arteries supplying the brain) and people in the top 25% of artery stiffness levbels were found to be the ones at risk.

This stiffness in arteries increases with age but not equally in all people. It is worse when the persion has more risk factors for cardiovasvular disease but there is probably a genetic component also. It probably acts to accelerate the development of dementia and in doing may cause about 20% of dementia.

To date the only treatment that helps is lowering blood pressure.

 

As people get older, it is more likely that their dementia will occur as a mixture of Alzheimer’s Disease and vascular dementia.

 

Delaying dementia is very important

As dementia is predominantly a disease of old age, delaying its onset can actually prevent it in some people as they will die of something else before dementia becomes a problem. It has been caculated that if we could delay dementia in the entire population by 2 years it would reduce the incidence of the disease by 20% and if we could delay it by 5 years then the incidence would halve. So while we can't cure it, by delaying it in many cases we can reduce the time a person lives with it, sometimes completely.

ementia develops over many years; prevention needs to start from age 3044

Alzheimer's Disease: The accumulation of beta amyloid in Alzheimer's Disease starts occuring several decades before the appearance of disease symptoms. i.e. the beta amyloid accumulation process occurs slowly over about 20 to 30 years. Thus, prevention strategies need to commence when people reach forty (or even earlier).

Vadcular Disease: In dementia due to vascular disease, those vascular changes have been occuring for probably since birth and certainly from early adult life. This is a very important point as it means that people who take steps to reduce their risk factors for vascular disease from early on in their adult life can significantly reduce their likelihood of developing the disease.

Dementia and depression

Depression can present in a very similar fashion to dementia in older people. As depression is a very treatable condition and dementia is not, It is very important when making a diagnosis of dementia to make sure the possibility of depression has been excluded. (Obviously the two conditions can co-exist. Many people with dementia develop some degree of depression after being told they have the condition.)

On the other hand, depression is a significant risk factor for dementia and about 10% of Alzheimer's disease is thought to be due to drepression.

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Treatment – Currently available treatment options for dementia provide little benefit

At present there is no effective treatment for either conditions. A few drugs are available but these at best delay symptoms about six months, although in some patients the benefit can last up to two years. (This can be very valuable but is not a cure.) The most commonly prescribed medications (2018) are donepezil, galantamine, rivastigmine and memantine. The herbal remedy Ginko has also been shown to be of benefit, but is no better than medications. (Ginko has fewer side effects than medications but does interact with some medications and anyone taking the Ginko needs to inform their doctor.)

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Prevention

Luckily, there are prevention strategies that can significantly reduce the risk of dementia occurring or delay its occurrence.

Over 30% of illness caused by dementia is caused by risk factors for cardiovascular disease, many of which can be beneficially modified, and other modifiable lifestyle risk factors. (See below.) Much study still needs to be done regarding this topic and a significant amount of the available evidence is not conclusive, partly because it comes from looking at populations. (These ‘observational studies’ can be difficult to interpret, as can studies about the influence of certain types of food or food constituents.) Thus many of the recommendations state that there is a probable rather than convincing association.

 

Source: Australian Institute of Health and Welfare: Australian Burden of Disease Study 2011

 

Prevention strategies for adults where evidence of benefit is convincing

Convincing evidence regarding strategies to prevent dementia relate primarily to reducing vascular disease risk factors. People who have multiple cardiovascular disease risk factors have been shown to increase vascular dementia risk by two to three times. Blood pressure is the most important risk factor.

While improving risk factors at any age is beneficial, it is very important to realise that the benefits provided by improving the risk factors below are cumulative over time. In other words, the benefit gained is directly related to how early in life the change is implemented and the number of years the improvement is maintained.

 

A. Reducing cardiovascular risk factors, especially hypertension

1. Maintaining a normal blood pressure

High blood pressure, especially in midlife, is thought to be responsible for about 5% of Alzheimer's disease and there is very good evidence that maintaining a healthy blood pressure level throughout life reduces dementia risk. It is important that this is continued into older age and thus it is very unfortunate that many older Australians have higher blood pressure, either because they:

Older people who have high blood pressure that is well treated have been shown to reduce their risk of dementia by about half and they also significantly reduce their risk of having a stroke. A blood pressure over 140 / 90 is often stated as the level at which treatmentshould be started but there is evidence that a lower level of 120 / 80 provides additional benefit in reducing dementia.
Everyone needs to monitor their blood pressure. This topic is dealt with in detail in the hypertension topic in the section on preventing heart attacks and strokes.

2. Not smoking

This increases the risk of vascular dementia by up to 80% and can influence Alzheimer's disease. It is reponsible for about 14% of dementia. (Of course, for many smokers Alzheimer's Disease ends up not being a problem as they die from diseases such as lung cancer, heart attacks etc etc relatively early on in life; before Alzheiners occurs.)

Importntly, the increased risk of Alzheiner's Disease that occurs with smoking greatly reduces as soon as smoking is stopped.

3. Being physically active on a daily basis is very important

It is important to be physically active on a daily basis and the intensity of activity is important. (A leisurely stroll is not enough. You do need to get a bit puffed.) However, moderate aerobic activity is all that is needed, such as brisk walking or riding an exercise bike. It is thought that adequate exercise alone can reduce the incidence of Alzheimer's Disease by 15% worldwide and in developed countries like Australia, where education levels are high and exercise levels low, it is responsible for 20% to 30%; and it can increase cognitive (thinking) ability in people (both young and old) who do not show dementia symptoms.

Adding some resistance training (e.g. some weight lifting) to the aerobic exercise can provide additional cognitive benefit.

To achieve optimum cognitive benefit from exercise, it is recommended that adults should do 150 minutes of moderately intensive physical activity per week (30 minutes a day five times a week).

There is also evidence that combining physical activity with cognitive activities is also beneficial. This can be done together, such as when doing complicated physical activities such as dancing, or by alternating physical and cognitive activites.

The reasons that exercise improves cognition are probably complex and include direct effects on the brain, such as increasing the production of nerve growth factors that stimulate the formation of nerve fibre connections and increasing the size of the brain memory regions (the hippocampus) and benefits to the cardiovascular system such as lowering blood pressure and reducing te risk of diabetes. Improvements in mood and mental health that occur with exercise are also significantly beneficial.

Another good piece of news is that people with an increased risk of dementia, determined by having a large amount of amyloid protein in their brain, especially benefit from exercise. They show a slower rate of decline in cognitive ability but not a reversal of any memory loss.

And of course exercise helps bone health, reduces the risk ofd some cancers (especially bowel and breast cancers), and helps reduce blood pressure, weight and the risk of diabetes.

4. Avoiding mid-life obesity (See obesity section)

Midlife obesity causes about 2% of Alzheimer's deases. (Obesity over the age of 75 years has not been shown to be a risk factor.)

5. Maintaining a high level of HDL Cholesterol (good cholesterol)

6. Avoiding diabetes (See section on diabetes)

7. Consuming a healthy diet based on the Meditteranean diet and fish or alternatively an Eastern diet

  • Meditteranean Diet: This is a plant based diet using unrefined foods; vegetables and fruits (the most important ingredients; the more colours the better), nuts, legumes, seeds, plant-based spreads / oils (especially olive oil). Dark geen leafy vegetables contains important antioxidants such as lutein and nitrates, which can help protect blood vessels. The diet is also low in sugars, which helps reduce the development of insulin resistance and diabetes. People who consume a Meditteranean diet have also been shown to live longer. In this diet, total dietary fats should less than 30% of energy in the diet and staurated fat should provide less than 8%.
  • Eating at least two servings of oily fish each week. (A significant part of this effect is probably due to the presence of heavy chain omega 3 fats which have several beneficial effects including an anti-inflammatory effect and a neuroportective effect, as they form an important part of nerve cell membranes. However, a significant part of the effect may just be due to the fact that people eating fish have a healthier diet.) There is no evidence that mercury present in small quantities in fish increases dementia risk.
  • Eastern diet: A similar Eastern diet that is high in vegetables and fruit and fish and low in animal products is also suitable.

 

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B. Mental activities and higher education levels

Cognitive training activities work best when the activitiys are both new to the person and challenge the person; and combining it with social interaction is also beneficial. It is important to realise that new activities are only new whhen you start them. The person becomes accustomed to them with time and their benefit is reduced. Therefore, to gain maximum benefit, for new, challenging activities need to be continually adopted.

Combining the above lifestyle choices is especially beneficial; for example, socialising or participating in cognitive activities (e.g. playing chess) with eating and / or exercise.

One possible reason that adopting the lifestyle options mentioned above provides benefit with respect to memory is that it looks like it may increase the amount of slow wave sleep an individual experiences. Slow wave sleep is important in maintaining memory functioning and unfortunately the amount of slow wave decreaases with age.

 

C. Other influencing factors

 

Prevention strategies where evidence of benefit is probable

Prevention

Initiatives in childhood that can increase cognitive reserve and help prevent dementia many decades later

Internet-based interventions / apps for dementia prevention

Obviously helping all the ageing population to reduce their dementia risk is a huge task. One way of making this task more manageable is to administer the couse online. Important elements of such a program are that they are best delivered by a brain coach, something that is difficult for online interventions, and that they need to address multiple issues.

At present there are several studies assessiung different internet-based interventions for reducing the incidence of dementia. One large one with over 6,200 participants (conducted by the Centre for Healthy Brain Ageing at the University of NSW and named the 'Maintain Your Brain' study) is taught in four modules each lasting about 10 weeks. (Not everyone needs to do all four modules.) These modules are then being reinforced over the next two years. To be successful such interventions need to employ multiple strategies and this study covers four areas; physical activity, nutrition, brain training and a module to help reduce depression. The results are still some way off.

There are many programs / apps available for improving memory alone. (Two commonly used ones are Fittness for Your Brain by NeuroNation and Luminosity. However, there is no evidence that any currently (September 2019) available cognitive app prevents the onset of dementia.

 

Therapies, treatments and factors that do not have good evidence of benefit or harm with respect to dementia

 

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Further reading on dementia

Its never too late to change your mind. The Latest Medical Thinking On What You Can Do To Avoid Dementia by Dr Michael J. Valenzuela. Published by ABC Books, Sydney, Australia, 2009.
This is an excellent book on current thinking about dementia with an emphasis on how it can be prevented.

 

Further information on mental illness

Mental health resources

Centre for Healthy Brain Ageing https://cheba.unsw.edu.au/research-projects/maintain-your-brain

Mental Health Branch of the Department of Health and Aged Care  www.mentalhealth.gov.au
This site provides information about crisis supports and contacts, general mental health information, mental health information brochures / publications about specific topics such as depression, anxiety, information about suicide prevention etc.
Ph 1800 066 247

Beyond Blue: The National Depression Initiative www.beyondblue.org.au

ybblue (Beyond Blue’s youth program)  www.youthbeyondblue.com
Beyond Blue’s youth program

Black dog institute www.blackdoginstitute.org.au
Provides information for clinicians and patient education.

Black dog institute for young people aged 12 to 18 years www.biteback.org.au
Provides information for clinicians and patient education.

Sphere (For GPs) www.spheregp.com.au
Sphere is a national education health project aimed at increasing GPs rates of identification, effective treatment and management of common psychological problems.

Moodgym   www.moodgym.anu.edu.au
An interactive program of CBT, more aimed at depression, developed by the Centre for Mental Health Research at the Australian National University.)

Reachout www.reachout.com.au
A resource for young people with depression.

Self-Injury www.self-injury.net
A web site with information about youth self-injury; an increasing problem in western society. It is run by a young adult who has previously self injured and gives information about overcoming the problem.

Lifeline www.lifeline.org.au  Ph 13 1114
Lifeline provides an immediate counseling service for all people)

Kids Help Line www.kidshelp.com.au
A national 24 hour counseling service for children and young people)
Ph 1800 551 800

CRUfAD, The Clinical Research Unit for Anxiety and Depression www.crufad.com 
CRUfAD is a group of researchers and clinicians concerned with anxiety and depression. It is a joint facility of St Vincent's Hospital Ltd and the University of New South Wales in Sydney, Australia. The self-help section of the web site has useful information about both anxiety and depression for the general public.

Anxiety Panic Hub www.panicattacks.com.au
A consumer web site with a focus on meditation / mindfulness.

The Panic Anxiety Disorder Association www.panicanxietydisorder.org.au 
Provides good consumer information

Toughin it out  www.toughinitout.com  
A program detailing survival skills for dealing with suicidal thoughts.

Mindmatters   http://cms.curriculum.edu.au/mindmatters/index.htm
A program that introduces mental health education to secondary schools.

Inspire Foundation  www.inspire.org.au/   
For people aged 14 to 25

National e-Therapy Centre Swinburne University  www.anxietyonline.org.au  
Help with all types of anxiety disorders

 

Further reading on mental health topics

Rapee, R., Spence, S., Cobham, V. and Wignall, A. Helping your anxious child. A step by step guide for parents. New Harbinger, 2000.

Macquarie University Child and Adolescent Anxiety Unit
This unit runs 12 week courses for anxious children in the 6 to 12 year age group.
www.psy.mq.edu.au/muaru.

Rapee, R.M. (2001). Overcoming shyness and social phobia: A step by step guide. Sydney: Lifestyle Press.
Deals with social phobias and shyness

Wells, A. (1997) Cognitive therapy of anxiety disorders; a practice manual and conceptual guide. Chichester. John Wiley and Sons, 1997.
  
Beating the blues by Susan Tanner and Jillian Ball. Published by Susan Tanner and Jillian Ball. Distributed by Tower books.
A good book for issues dealing with the treatment of depression.

Don’t panic. Overcoming anxieties, phobias and tensions by Andrew Page. Published by Liberty One Media.
Deals with panic disorders, phobias and anxiety.

Aisbett, B. Living with it; a suvivor’s guide to panic attacks. Pymble, NSW. HarperCollinsPublishers, 1993.

Aisbett, B.Taming the black dog. Pymble, NSW. HarperCollinsPublishers, 2000.

Calrk, S. After suicide: help for the bereaved. Melbourne. Hill of Content Publishing Company Pty Ltd, 1995.

 

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