When to worry about memory loss

Dr Kevin McCarroll offers signs of memory loss and how to cope with it.

Key to the concept of successful ageing is not only maintaining our physical and mental health, but crucially our cognitive abilities and memory. Concerns about memory are common in later life ranging from subjective complaints in the worried well, to mild cognitive impairment and dementia.

Trying to decipher what’s normal or significant can be difficult, particularly in the early stages of a memory problem. So what should we expect of our memory as we get older and when should we be concerned?

Some degree of cognitive decline is a normal part of ageing and, indeed, studies show that even in our 40s, brain processing speed diminishes. In fact, in middle age, hundred of thousands of brain cells are dying every day. But not to worry, there is a considerable built in brain reserve and the effect is small and offset by a better skill set, knowledge and experience. Furthermore, there is compelling evidence that variation of lifestyle factors may protect against cognitive decline.

Understanding the ‘nuts and bolts’ of why we forget things is key to diagnosing and approaching any memory problem. In essence, acquiring new memories requires us to efficiently pick up information and, depending on the complexity, it demands different degrees of intellectual processing. Secondly, we need the ability to store new memories and lastly have the capacity to retrieve or pull out memories.


Poor attention and concentration for a variety of reasons, including stress, depression, poor sleep, pain, medications, vascular brain damage and certain endocrine disorders, can all affect our ability to pick up and retrieve information. When this happens infrequently, it is often of no import. Indeed, absent mindedness and difficultly with retrieving a word or name is in general nothing to worry about.

Similarly, occasional lapses of attention like forgetting why we went upstairs or where we left an object is common.

However, when it becomes frequent or interferes with important things in our day-to-day lives, then it may be a cause for concern. In particular, any ongoing decline in memory needs to be investigated and any of the above causative or aggravating factors identified.

Whilst patchy memory loss may have a benign cause, rapid forgetfulness on a consistent basis (due to difficulty in storing new memories) is generally more concerning. This inability to remember most new (and often important) things is more suggestive of Alzheimer’s disease, particularly when there is a progressive decline.

It is often associated with repetitive questioning, but early preservation of long term memories already stored in the brain.

But can we do anything to reduce the risk of developing memory problems and even Alzheimer’s disease? Well, in recent years, there has been a growing emphasis on ‘brain health’ and of the importance of lifestyle factors in maintaining good brain function.

In general, it appears that what’s good for your heart is also good for your brain. Indeed, even in the absence of dementia, brain shrinkage can vary hugely in individuals of the same age, and is accelerated by several factors including excess alcohol intake.

Increasing evidence suggests that early brain changes may precede the development of Alzheimer’s disease by decades. Smoking, diabetes, high blood pressure, obesity, cardiac disease, depression and lack of physical and mental activity have all been established as independent risk factors for Alzheimer’s. The same factors are also associated with hardening of the arteries in the brain which of itself can directly case memory problems.

Whilst Alzheimer’s remains the commonest cause of dementia (70%) and there are no drugs to slow the disease down, two medications which correct chemical imbalances in the brain do help in a proportion of patients.

Furthermore, in the early stages, it is compatible with leading a very good quality of life with many continuing to engage in several of the usual activities of daily living including driving. Recent studies in Britain show that the average age at diagnosis has increased, which may reflect better control of vascular risk factors and better general health.

There is limited good quality evidence assessing the affect of treatments on cognitive dysfunction. High dose B multivitamins appeared to prevent brain shrinkage in one study of older adults with mild cognitive impairment, though findings have yet to be replicated.

In addition, a review of nine placebo controlled trials of gingko biloba published this year, suggests a stabilising effect on cognition, including in those with dementia

Aside from this, there are number of things that may improve general memory function or help get around the problem posed by forgetfulness. Avoiding stress, anxiety, alcohol excess and ensuring good sleep is advised. Practical measures like getting fresh air to maintain your level of alertness, and deliberately being mindful of what we do can be helpful.

Mental games

Whilst mental games such as sudoko might intuitively seem beneficial, evidence as to any affect on general cognition is lacking. However, keeping up a good level of mental stimulation is in general recommended, as there is probably some truth in the notion of ‘use it or lose it’.

Compensatory strategies like writing things down, using phones alarms for reminders and establishing routines can be helpful.

In summary, there are several underlying reasons for memory problems. Some may be due to treatable medical conditions such as an underactive thyroid disease or depression/anxiety. Other causes may be addressed by changing lifestyle factors which may also protect against future memory loss.

If you have unexplained memory loss or your memory is getting worse, then you should visit your GP for further assessment.

Dr Kevin McCarroll is a Consultant Physician in Geriatric Medicine, St James’s Hospital, Dublin.