Alcohol and memory

Published 1 December 2009.

The human memory is a complex process, involving memorisation, retention and recall. If one of these processes is disrupted, we cannot remember things. Alcohol interferes with memory – something we will all be aware of after a big night. In addition to memory, excessive and prolonged alcohol consumption also affects other cognitive functions, such as concentration and alertness.

What is memory?

Memory is often used synonymously with recall but in reality it is a much more complex function. Memory begins with perception but only a tiny proportion of our sensory experiences will pass through the filter and end up in our working memory.

Our working memory could be compared to a computer desktop – it is used to store only the things we are working on at that very moment. If we process a piece of information enough, it will be transferred from the working memory to the long-term memory. In order to remember, we must also be able to transfer information from our long-term memory back into our working memory. Mistakes can happen at any point in the process, causing us to forget.

Where is our memory located?

The hippocampus is the brain’s memory system. It is located in the temporal lobe, close to the ears. Conditions such as Alzheimer’s disease cause damage to the hippocampus, which explains the memory loss typical of this condition. However, our memories are not located in the hippocampus as such, as other structures of the brain are also involved. As we have explained above, memory is a complex process affected by a number of other functions.

Alcohol and memory

Alcohol induces a sense of relaxation and well-being. Unfortunately, it also causes your brain to slow down and work less quickly and efficiently than it otherwise would. Just one drink-fuelled night can cause memory loss, at worst wiping out all your recollections from that period of time. Even a one-off drinking session is enough to damage the brain.

Our working memory is particularly susceptible to the effects of alcohol. Here, the problem is not the lack of recall from the night before. In fact, the damage has taken place the previous night as alcohol impairs our recall. Even the following day, the hangover will affect our ability to generate memories and our concentration and attention will be impaired.

Heavy alcohol intake can cause not just momentary lapses of memory, but also structural changes in the brain. Alcohol intoxication destroys brain cells. Approximately half of all heavy drinkers will suffer from memory loss and an impaired ability to learn new things. Dementia-like symptoms are apparent in 10% of all heavy drinkers. It is important to bear in mind that the recommended daily allowance is not the same as a healthy daily dose!

Primary alcoholic dementia, the medical term for cognitive impairment caused by alcohol toxicity, is a highly controversial diagnosis as there is currently no evidence to support a direct link between alcohol and permanent dementia. What is known, however, is that the longer the alcohol abuse continues, the more extensive the neurological changes and the more challenging the recovery.

The term alcoholic dementia is used to describe a set of symptoms, including loss of short-term memory, personality changes, difficulty socialising, difficulty maintaining steady employment and a deterioration in mental acuity. It is also associated with changes in motor function including claudication, loss of balance and tremors. All cognitive disease is characterised by loss of function.

Alcohol exacerbates a number of risk factors which can lead to dementia-like symptoms. Heavy alcohol use is often associated with strokes, accident-related brain damage and vitamin deficiencies caused by a poor dietary intake. A number of memory-related diseases, including Korsakoff’s syndrome, Wernicke’s disease and Marchiva-Bignam’s disease, have been defined by medical professionals.

A brain-healthy lifestyle

Young people’s brains are more vulnerable to damage as the brain is still developing. Youth offers no protection from the toxic effects of alcohol and alcoholic dementia. Even someone in their thirties can develop this condition if they have been drinking heavily from a young age.

Heavy alcohol use is often associated with other unhealthy habits. Lifestyle considerations are particularly important in middle age, as a brain-smart lifestyle at this period in your life will offer you protection into old age. Alcohol abuse, smoking, excess weight and lack of exercise are all risk factors for cognitive disease in the elderly. The more unhealthy your lifestyle and the longer your habits persist, the greater your chances of developing memory impairment later in life.

The good news is that alcohol-related neurological changes can be reversed if alcohol use is discontinued. The human brain is a remarkably adaptable organ and can recover from quite significant damage. Just a few weeks without drinking will clear the mind – it’s never too late to make a change!

Heidi Härmä
Project Officer
Muistiliitto ry (The Alzheimer Society of Finland)