Non-epileptic seizures and functional (dissociative) seizures
Non-epileptic seizures (NES) or functional (sometimes called dissociative) seizures may look similar to epileptic seizures but they are not caused by abnormal electrical activity in the brain. This page will help you understand what non-epileptic seizures are, what causes them, how they are diagnosed and how they can be treated.
Seizures that are not due to epilepsy
There are several different types of seizures, and they can happen for many different reasons. Epilepsy and epileptic seizures are explained below.
Seizures that are not due to epilepsy are sometimes called 'non-epileptic seizures'. They can have a physical cause such as low blood sugar (hypoglycaemia) or may be related to how the heart is working. Or they may have a psychological cause. The most common type of non-epileptic seizures (NES) is functional (sometimes called dissociative) seizures (see below).
What causes epileptic seizures?
Epileptic seizures are caused by a disturbance in the electrical activity of the brain (so they always start in the brain).
Up to 30% of adults diagnosed with epilepsy who are then assessed at specialist epilepsy centres are found to have NES
This may be partly because epilepsy and NES can look very similar, and can affect people in similar ways. However, non-epileptic seizures are not caused by disrupted electrical activity in the brain and so are different from epilepsy. They can have a number of different causes.
Functional (dissociative) seizures
Some NES are caused by mental or emotional processes, rather than by a physical cause. This type of seizure may happen when someone's reaction to painful or difficult thoughts and feelings affect them physically. These are called functional seizures.
These NES used to be called 'pseudoseizures’. This name is unhelpful because it suggests that the person is not having 'real' seizures or their seizures are deliberately 'put on'.
Functional seizures happen unconsciously, which means that the person has no control over them and they are not put on. This is the most common type of NES.
Functional seizures are sometimes known as non-epileptic attacks. People who have non-epileptic attacks may be described as having 'non-epileptic attack disorder' (NEAD).
These terms are not always helpful because they describe the condition by saying what it is not rather than saying what it is.
The newer name of functional seizures is more helpful because it does not describe seizures in terms of epilepsy.
However, it can be confusing as sometimes doctors use the terms NES or NEAD when they are talking about functional seizures. Other terms for functional seizures are dissociative seizures or psychogenic seizures.
What causes functional seizures?
We all react to frightening or stressful situations differently. When we are frightened we might feel physical symptoms such as a racing heartbeat or a sweaty feeling. When we feel sad, we might cry. So how we feel emotionally can sometimes cause a physical reaction.
An extremely frightening or upsetting experience may be so emotionally difficult for some people to think about that they cannot consciously cope with how this makes them feel.
In some cases, they will unconsciously hide or 'repress' the memory of these events. These memories may always remain hidden and we may never remember the events that have happened.
For some people, the memories of these painful past events can suddenly come up or intrude into their thoughts or awareness. This might happen during an emotional or stressful situation or when there is something in the environment that unconsciously triggers a distressing memory.
Functional seizures can happen as a cut-off mechanism to prevent bad memories being relived. The person splits off (or dissociates) from their feelings about the experience because it is too difficult to cope with. The seizure happens because their emotional reaction causes a physical effect.
These seizures are an unconscious reaction so they are not deliberate and the person has no control over them.
Functional seizures are like the body's way of 'drowning out' a frightening or painful memory so that it doesn't enter into our thoughts.
Any experiences that we have, whether good or bad, can have a deep and long-lasting effect on us, and everyone has their own way of dealing with them. Functional seizures are often caused by traumatic events such as:
- major accidents
- severe emotional upset (such as the death of a loved one)
- psychological stress (such as a divorce)
- difficult relationships
- physical or sexual abuse
- being bullied.
It can be hard to find the cause of someone’s functional seizures. For some, they start shortly after a specific event. For others, they may not start until years later or they may start suddenly for no apparent reason. Once functional seizures have started, they might be triggered, or brought on, when the person is stressed or frightened. Or they might happen spontaneously in situations that are not stressful or frightening. Some people with functional seizures may not recognise their feelings of stress before a seizure, and so may not understand why the seizure has happened.
Sometimes, even the fear of having a seizure can, in itself, trigger a seizure.
Finding the original event that caused the dissociative seizures to start might help to find a way to treat the seizures. But this is not always possible and it can be hard to talk about traumatic or difficult events.
Seizures caused by a delayed response to a very stressful event or situation, for example, being in a war or a disaster, are a response past events. These seizures may be part of a post-traumatic stress disorder (PTSD) – a condition that sometimes starts after a traumatic event. During the seizure the person may cry, scream, or have flashbacks (sudden, vivid memories of the event). They may not remember the seizures afterwards.
What are the symptoms?
Although functional seizures start as an emotional reaction, they cause a physical effect, such as palpitations (being able to feel your heart beat), sweating, a dry mouth, and hyperventilation (over-breathing).
Some features of functional seizures are very similar to epileptic seizures. These physical features may include loss of awareness, loss of sensation, and loss of control of bodily movement.
Who has functional seizures?
Functional seizures can happen to anyone, at any age, although some factors make functional seizures more likely. Functional seizures are:
- more common in women
- more likely to start in young adults
- more likely to happen to people who have had an injury or disease or who have had severe emotional upset or stressful life events
- more common in people with other psychiatric conditions (such as depression, anxiety, personality disorders, or people who self-harm).
How are functional seizures diagnosed?
If you have seizures, your GP will usually refer you to a specialist for diagnosis. This will usually be a neurologist (a doctor who specialises in the brain and nervous system) to see if the seizures are epileptic. Or you may be referred to a psychiatrist or psychologist (as functional seizures are usually classified as a psychiatric condition).
It may be easier for doctors to try and rule out possible physical causes first, including epilepsy. This will influence the types of tests you might have.
Functional seizures can be difficult to diagnose because they can appear similar to epileptic seizures. There are no symptoms that will definitely identify functional seizures from epileptic seizures.
The specialist will ask you about what happens to you during a seizure. If you don’t remember your seizures, you might like to bring someone to the appointment who has seen your seizures.
Some tests are used to rule out other causes of seizures, including epilepsy.
- Medical examinations and blood tests can be used to check your overall health and see if your seizures have a physical cause such as diabetes.
- Brain scans such as CT (computerised tomography) or MRI (magnetic resonance imaging) are used to form a picture of your brain.
If the tests show no neurological or physical cause for your seizures, and your specialist thinks it might be functional seizures, you may be referred to a psychiatrist or a psychologist for diagnosis.
Treatment may depend on the cause of your seizures, and your medical history. Your specialist may talk to you about what treatment options might be helpful.
Seizures that are not epileptic will not be controlled by anti-seizure medication (ASM).
If you already take ASM, for example if you were previously diagnosed with epilepsy, your specialist may suggest you gradually reduce them. If you have functional seizures and epilepsy, you will usually continue to take ASM for your epileptic seizures.
If you also have anxiety or depression, your specialist might talk to you about whether other medication, such as anti-depressants, might be helpful.
Other forms of treatment
Psychotherapy is the recommended treatment for functional seizures. Psychotherapy is the name for a group of different ‘talking’ therapies (treatments). Mental health professionals, including psychiatrists and psychologists, are trained in different forms of psychotherapy.
Cognitive behavioural therapy (CBT) is often recommended. CBT looks at how you think about things, how this affects you physically and emotionally, and how it affects what you do (your behaviour). By changing the way you think about things, such as how you think about yourself, other people, and the world around you, this may change the way that you behave. CBT tends to focus on how things are affecting you in the present, and ways to help you to view current situations more positively, and cope with stressful events.
CBT can take several months or longer as it may take time for you to feel comfortable talking about your experiences and feelings.
See more about epilepsy treatment.
How you feel about your diagnosis
Being diagnosed with functional seizures can feel quite scary or upsetting because of the stigma around how psychiatric conditions are sometimes viewed. Understanding that dissociative seizures can be your body’s natural way of reacting to stressful situations might be helpful.
There is no ‘right’ way to feel about your diagnosis, but being able to accept it can be part of helping to improve your seizure control.
You might like to call our confidential helpline to talk about your diagnosis and how you feel about it.
Other types of non-epileptic seizures
There are other types of NES and these can be divided into two types: those that have an organic cause and those that have a psychological cause.
NES that have an organic cause
These seizures have a physical cause (relating to the body). They include fainting (syncope) and seizures with metabolic causes such as diabetes.
Because organic NES have a physical cause, they may be relatively easy to diagnose and treat.
NES that have a psychological cause
In addition to functional seizures, there are other types of seizures that have a psychological cause:.
- Panic attacks can happen in frightening situations, when remembering previous frightening experiences or in a situation that the person expects to be frightening. Panic attacks can cause sweating, palpitations (being able to feel your heartbeat), trembling, and difficulty breathing. The person may also lose consciousness and shake.
- Factitious seizures means that the person has some level of conscious control over them. An example of this is when seizures form part of Münchausen’s Syndrome, a rare psychiatric condition where a person is driven by a need to have medical investigations and treatments.
Whatever type of seizures you are having you might like to talk to someone about your diagnosis and how you feel about it.
Call our confidential helpline if you want to talk.
Living with non-epileptic seizures
The general first aid guidelines for dissociative seizures are the same as for epileptic seizures:
- keep the person safe from injury or harm: only move them if they are in danger
- if they have fallen, put something soft under their head to protect it
- allow the seizure to happen, don’t restrain or hold them down
- stay with them until they have recovered.
Keep a normal routine if possible
For some people, NES may disrupt their daily life or they may want to avoid activities in case they have a seizure. However, studies show that it can help to keep as normal a routine as possible, and to try to take part in activities with other people. This may help to avoid becoming isolated and anxious, which may make seizures more likely.
Treatment for NES may work best when someone is active in life, including working, studying, or taking part in other activities which are meaningful and satisfying.
If you are working, your employer has a responsibility to keep you and other employees safe at work. To do this, they may need to know about any medical conditions that affect you at work, including NES.
Your employer may need to do a 'risk assessment' to see if your condition may affect safety at work.
See our information on employment.
Financial help and benefits
You may be able to apply for financial help, depending on how your seizures affect you. Whatever the cause, seizures can affect different areas of life for some people.
Find out more about what help is available.
Driving regulations for functional seizures
Driving regulations for the UK are set by the Driver and Vehicle Licensing Agency (DVLA). You will need to stop driving and contact the DVLA to check the regulations for functional seizures.
Visit gov.uk/driving-medical-conditions for more information.
Find out more about driving and epilepsy
Seizures and disability
The Equality Act 2010 aims to protect people against discrimination if they have a disability.
Someone has a disability if they have "a physical or mental impairment which has a substantial and long-term adverse effect on the ability to carry out normal day-to-day activities".
To be protected by the Equality Act you need to show that you meet the definition above.
- STARS (Syncope Trust And Reflex anoxic Seizures) provides support and information on syncope and reflex anoxic seizures.
- FND Action – raises awareness of Functional neurological disorder (FND) and Non-epileptic attack disorder (NEAD). Provides support across the UK
- Counselling Directory – find a counsellor or therapist in your area. Your GP or specialist may also refer you for counselling or psychotherapy.
- British Association for Counselling and Psychotherapy – The professional association for members of the counselling professions in the UK and have a register of trained therapists.
- FND Hope
Information and research on Functional Neurological Disorder (FND).
Epilepsy Society is grateful to
Dr Suzanne O’Sullivan, consultant neurologist and neurophysiologist at the National Hospital for Neurology and Neurosurgery and Epilepsy Society, who reviewed this information.
Information updated: August 2023