What is dementia?

Many people are uncertain about what dementia is. Dementia is actually an umbrella term for a large number of disorders that can affect thinking and memory. The most common form of dementia is Alzheimer’s Disease, which currently accounts for between 50 and 70 per cent of dementias.

The second most common form of dementia, resulting from small strokes, is commonly called Vascular Dementia but is also sometimes called Multi-Infarct Dementia (MID). It is now believed that Alzheimer’s Disease and Vascular Dementia occur together, as a mixed cause dementia, in up to 30 per cent of individuals.

Other types of dementia include Lewy Body Dementia and Fronto-temporal Dementia. These account for the majority of the remaining dementias. A variety of neurological and medical conditions may also result in some dementia but these are relatively rare.

Alzheimer’s Disease is characterised by changes to some of the nerve cells within the brain. Over time these changes result in cell death. Proteins are one major kind of chemical in the body, normally making up tissues like muscle. Some other proteins can deposit on the nerve cells in the brain, forming what are called ‘neuritic plaques’. These interfere with the normal transmission of information between brain cells. Tangles can form from broken down portions of nerve cells, again interfering with how the brain cells function. While there are many theories about why these changes in brain cells occur in some individuals, no one explanation has yet been accepted. In fact, there probably is not one single cause of the disease, but several factors that affect each individual differently. The condition is slightly more common in women than men.

Vascular Dementia occurs when blood clots block small blood vessels in the brain, ultimately destroying surrounding brain tissue. The disease can also trigger minor strokes. Lewy Body Dementia involves a special kind of brain cell death occurring in particular areas of the brain.Patients with this disorder often demonstrate extreme variation in mood with periods of confusion, followed by greater lucidity, and disturbed visual experiences. This kind of cell death is found in patients with Parkinson's Disease and some other conditions. Fronto-temporal Dementia is a disease where cell death occurs in specific parts of the brain (the frontal and temporal lobes). It is important because it is often associated with significant behaviour and personality change.

Risk factors

For most dementias, the leading risk factor is increasing age. Approximately 10 per cent of all individuals over age 65 have some dementia, half with early or mild dementia and half with moderate or severe dementia. The incidence of dementia in the population seems to double every five years of age, starting with 0.8 per cent at age 65, then 1.8 per cent at age 70, then 7.2 per cent at age 80, rising to around 30 per cent by age 90.

There are specific risk factors associated with the individual types of dementia. Factors which increase risk of Alzheimer’s Disease include having a family history of the disorder, having a history of head injuries or strokes, and having a history of depression, particularly if the first episode of the depression occurred later in life. Factors which increase the risk of Vascular Dementia include a family history of strokes and vascular disease, a personal history of hypertension (high blood pressure), strokes or vascular disease, and risk factors associated with heart disease such as cigarette smoking and obesity. Risk factors for Lewy Body Dementia and Fronto-temporal Dementia are less well understood at this time.

Symptoms of dementia

The symptoms of Alzheimer’s Disease usually appear slowly, increasing in severity over time. At first, the only symptom may be mild forgetfulness. In this stage, people may have trouble remembering recent events, activities, or the names of familiar people or things. They may not be able to solve simple math problems. Such difficulties may be worrisome, but usually they are not serious enough to cause alarm.

However as the disease progresses, symptoms are more easily noticed and may become serious enough to cause persons with the disease or their family members to seek medical help. For example, people in the middle stages of the disease may forget how to perform simple tasks, such as brushing their teeth or making a cup of tea. Their thinking may become muddled and problems arise with speaking, understanding, reading or writing. Later, persons with Alzheimer’s Disease may become anxious or aggressive, or wander away from home. Approximately 25 per cent of Alzheimer’s patients experience hallucinations or delusions during the course of their illness but usually only for a short period.

Symptoms of Vascular Dementia include confusion, problems with recent memory, wandering or getting lost in familiar places, loss of bladder or bowel control, emotional problems such as laughing or crying inappropriately, difficulty following instructions, and problems handling money. Usually the damage is so slight that the change is noticeable only as a series of small steps. However, over time, as more small vessels are blocked, there is a gradual mental decline.

As noted previously, the symptoms of Lewy Body Disease can often have a psychiatric quality –increased anxiety, some visual hallucinations and a general problem with concentration and persistence. The cognitive problems and speed of deterioration can sometimes be more rapid than Alzheimer's Disease but this can vary significantly. Fronto-temporal Dementia often shows itself first as changes in behaviour, mood or normal personality features but then will also include changes in cognitive skills, particularly attention, problem-solving, judgement and organising skills. As a result this disease can be quite distressing for family members and carers.


Currently there is no cure for either Alzheimer’s Disease or Vascular Dementia that can reverse damage that has already occurred in the brain. Treatment for dementia generally focuses on controlling current symptoms (such as agitation or depression) and preventing additional brain damage (for example, by controlling high blood pressure).

A number of psychological treatments and medications are useful in treating symptoms of dementia and enhancing the quality of life for all involved.

Psychological treatments

Behavioural and other psychological symptoms of dementia can be treated with a variety of non-pharmacological interventions. These fall into three main categories: psychological, behavioural and environmental.

Psychological approaches to treating symptoms of dementia include a number of ways to target specific areas of distress. For example, supportive and cognitive-behavioural interventions may be useful to assist with adjustment to the initial diagnosis and forward planning and in treating depression in early stage dementia. These interventions may be particularly useful at the initial time of diagnosis. Psychotherapy and psycho-educational interventions may assist carers both to cope with assisting the person with dementia and to maintain their own health and well-being. Memory training and using external memory aids can assist a person in early stages of dementia to maximise their cognitive functioning and independence. Encouraging referral to dementia support groups can help people to develop useful, supportive networks and realise the full extent of potential support services if or when required.

Behavioural approaches are useful in targeting troublesome behavioural patterns in persons with dementia. Difficult-to-manage behaviours may include wandering, agitation and repetitive questioning. A general approach to behavioural interventions involves identifying a target behaviour, gathering information on its possible triggers, setting up a plan to modify the behaviour over time (including rewarding desirable behaviours) and finally evaluating the success of the intervention. Behavioural interventions maximise the use of retained skills and can often utilise weaknesses to promote enjoyable activities. For example with poor concentration it can be easier to redirect a person to an enjoyable activity. In general, interventions that are individually tailored to suit a person’s unique context achieve the greatest success. Psychologists and some other health professionals can help in the design of such behavioural interventions.

Environmental approaches encourage creative solutions to dementia symptoms, targeting the environment of the person with dementia. The ideal environment for a patient with dementia is one that is non-stressful, constant and familiar. Sometimes features of the environment that may seem benign, for example television noise, confusing shadows and glare, may in fact be quite disturbing to an individual with dementia who is having trouble making sense of the environment. Some suggestions:

  • Minimising confusion by reducing choices, clutter, noise and glare in the environment;
  • Providing meaningful activities that the person with dementia is comfortable with and enjoys; this may also reduce boredom and agitation;
  • Introducing approaches such as music therapy and pet-assisted therapy that have also been successfully used with persons with dementia.

Drug treatments

Medication-based treatments for symptoms of dementia are often paired with non-drug treatments, like those above, for maximum effectiveness. Newer antipsychotic and antidepressant medications may prove effective in controlling symptoms such as hallucinations, delusions, anxiety, depression and physical aggression.

One class of drugs (called cholinergic drugs) includes medications that have a modest but definite effect on core symptoms of Alzheimer’s Disease, such as memory impairment. Cholinergic drugs provide measurable improvements in some individuals and may help improve memory and independent functioning in the short-term. However, the drugs do not appear to help all people, and their effects in all individuals with dementia are time-limited.

What to do?

Be well informed. There are self-help organisations and groups for dementia sufferers and their carers. You can find these on the internet by typing ‘dementia’ into your search engine, or you can find local groups by contacting your local Citizens Advice Bureau, council or health department.

Talk with your GP about choices of drug treatments and other resources that she or he may know about in your area.

Talk with a psychologist, especially about the psychological, behavioural and environmental strategies you can use to lessen the impact of dementia.