Memory problems

If you notice that your memory is poor, it is natural to think of the worst explanation – Alzheimer’s disease or another type of dementia. In fact, there is usually another reason and the problem is usually temporary.

Causes of memory problems
Depression is the most common cause of memory problems. With depression, many of the mental processes are slowed, and memory is particularly affected. Unfortunately, worry about memory loss can worsen the depression, producing a vicious circle.

Stress is another common cause of memory problems. Almost any worry or stressful life event can affect our ability to store and recall memories. When the problem is resolved, or time has healed the pain, memory becomes as efficient as it was before.

Normal ageing. During your mid-40s and 50s, it is quite normal to believe you have become more forgetful. Surveys find that 75% of people over the age of 50 report that they have had some ‘memory problem’ over the past year. But it may not be as bad as you think – young people forget things and do not bother about it, but older people take more notice o f their memory lapses and worry. Do not make the mistake of thinking that everyday memory lapses are Alzheimer’s disease – forgetting where you put your keys is not Alzheimer’s! We all occasionally put things in strange places (such as the keys in the fridge), but it is only when this sort of thing begins to happen regularly that there may be a problem.

A study of 111 people aged 90–100 years showed that over half had a strikingly good memory (Neurology 2003;60:477–80), so memory loss is not automatic as we get old. Other studies have shown that old people are better at judging whether people are honest or intelligent, so some aspects of mental function actually improve with age.

The ‘tip-of-the tongue’ phenomenon is a very common experience – your mind suddenly freezes when you need a crucial word, such as a name (often of someone you know well). This is more likely to happen if it is a name that you seldom speak aloud, because scientists believe you are simply having trouble retrieving the actual sound of the word from your memory bank of word sounds. It is a nuisance, but does not mean you are on the way to serious memory loss.

Alzheimer’s disease. Of course, a failing memory does occur with Alzheimer’s disease. Alzheimer’s is mainly a disease of the elderly. About 1% of people in their 60s, 20% of those over 85 years and 30% of those over 90 are affected.

Stroke. It is common to have some memory loss after a stroke, but this usually improves over the following 3–6 months.