Memory loss but not dementia: functional cognitive disorder (FCD)

What is functional cognitive disorder?

Functional cognitive disorder (FCD) is an under-recognised condition that is different from dementia.

In FCD, cognitive difficulties with memory and thinking – particularly when the person can’t maintain attention – are down to a problem with how the brain is working, rather than to loss of brain cells. 

FCD is different from diseases like Alzheimer’s in which brain tissue is permanently damaged. Although the cause of their symptoms is very different, people with FCD may be just as troubled by memory problems as people with dementia. 

In FCD, memory problems may stay the same over time, or come and go, or even get better. 

Unlike dementia, FCD does not generally get steadily worse over a period of years.

FCD only rarely leads to the worsening symptoms seen as dementia progresses and the severe difficulties experienced in late-stage dementia.

What can cause problems with memory and thinking?

A lot of people have cognitive problems, sometimes starting from middle age. For example, they might frequently misplace items, lose track of what they are doing, or not be able to follow the thread of a conversation.

Lots of things can cause symptoms like this. They include:

• anxiety
• depression
• early-stage Alzheimer’s disease or vascular dementia
• functional cognitive disorder (FCD)
• mild brain injury (concussion)
• vitamin and thyroid deficiencies. 

If you’re worried about your memory or thinking, call our support line on 0333 150 3456 or visit your GP. The doctor will talk to you about your concerns and arrange for further tests if necessary, most likely at a memory clinic.   

Is diagnosis of the cause of memory loss always accurate?

If you have dementia, an accurate diagnosis is key to getting the support to live well. If you have problems with memory or thinking, it can turn out this is not because of dementia. In this case, it's equally important for the cause to be found so you can be given the right treatment and advice.

When symptoms are relatively mild, it can be difficult to make a firm diagnosis even with a brain scan. This means there’s a chance that a few people will be discharged from a memory clinic after being told that nothing is wrong, even though they are still badly affected. This can leave the person – who may actually have FCD – living with a lot of uncertainty but little support.

For some people found to have mild cognitive impairment (MCI), the more specific diagnosis of FCD will give them an explanation for their symptoms, which rules out physical brain disease (i.e. is not a ‘pre-dementia’ condition).

A small number of people will be given a diagnosis of early dementia but later be found to have FCD.

What are the symptoms of functional cognitive disorder?

A person with FCD is likely to have all the symptoms above. They might also go ‘blank’ at times, for example when trying to remember a PIN, or need to read the same page of a book over and over. Many people with FCD have to use a lot more effort to concentrate and remember things, which itself is tiring. 

Memory difficulties in FCD happen when the brain has reduced attention to stay focussed on a task. We all have a limited capacity for attention – think how hard it is to focus on several things at once. So anything that detracts from our attention lowers our ability to learn and remember new information.

Some people with FCD become very worried that they have dementia so that they stop trusting their memory, causing a ‘vicious cycle’ and using up a lot of attention.

Some people have physical symptoms, chronic pain or disrupted sleep – which all cause problems with attention. Others get ‘stuck’ in particular thought patterns. 

For some people with anxiety or depression, their cognition can also be badly affected. FCD can happen without depression or anxiety, or sometimes these only partly explain why someone’s symptoms are as bad as they seem. In some cases, symptoms of FCD start after a mild traumatic brain injury (concussion).

How is functional cognitive disorder diagnosed and treated?

A doctor can diagnose FCD from talking to someone about their problems, from memory tests and when the person (and others around them) describes their everyday life.  

In FCD, memory and thinking work OK at times but not at all at other times. This variability helps doctors make the diagnosis.

Sometimes a person with FCD is more worried about their problems than those around them. Failure of symptoms to get steadily worse is also a feature of FCD, but will become apparent only with time. 

Just knowing that their problems are caused by FCD and not dementia can help a person with FCD to start to feel better.

Treatment for disrupted sleep, pain, anxiety and depression can all help. The GP will also review the medications someone is taking.

For more practical tips and suggestions on managing FCD, see the resources listed below. 

What if I’m not confident now about my dementia diagnosis?

A few people given a diagnosis of dementia will find that their symptoms don’t get worse over several years. A person experiencing this may not have dementia but something else, including FCD. 

Feeling uncertain about your dementia diagnosis is complicated. Even the thought that it could be changed will raise a lot of difficult questions, such as:

• Are you happy living with your current dementia diagnosis?
• Are you prepared to go through another set of tests and possibly scans?
• If it’s not dementia, how might you feel about everything you’ve been through?
• Will you and those close to you feel let down if your diagnosis still comes back as dementia?

Everyone is different and some people will not seek to change their diagnosis of dementia. But if you’re unhappy with your current diagnosis, speak to your GP – perhaps at an annual review. You can ask to be referred back to a memory clinic, preferably to the service that made your original diagnosis. 

Where can I find out more about functional cognitive disorder? 

Useful resources about FCD

• Neurosymptoms.org has an excellent factsheet about FCD
• Head Injury Symptoms has information about mild head injury 
• The memory handbook includes useful practical tips.