Dissociative identity disorder (DID): symptoms, causes and treatment

The NHS describes the main symptoms of DID as memory gaps about everyday events and personal information, and having several distinct identities. Dissociative disorders in general can include feeling disconnected from yourself and the world around you, forgetting certain time periods, events and personal information, feeling uncertain about who you are, and feeling little or no physical pain.

Some people with dissociative disorders have seizures, which can vary from fainting to something more like an epileptic seizure. Periods of dissociation can last hours or days, or for much longer, weeks or months.

• Feeling outside yourself and observing your actions from a distance (depersonalisation).

• Feeling that the world is unreal, foggy or lifeless (derealisation).

• Gaps in memory for personal information and events that are more severe than normal forgetfulness.

• Finding yourself in a place without knowing how you got there, which the NHS describes in dissociative amnesia.

Dissociative disorders are, in the NHS's words, a range of conditions that can cause physical and psychological problems. Dissociation is a way the mind copes with too much stress. The NHS names three main types: depersonalisation-derealisation disorder, dissociative amnesia and dissociative identity disorder.

DID is the most complex of these. Someone with DID may feel uncertain about their identity and who they are, and may feel the presence of other identities, each with their own names, voices, personal histories and mannerisms.

The NHS stresses that dissociation is a way the mind copes with too much stress, and that periods of dissociation can be short or last for much longer. DID sits at the more severe end of this range.

Rethink Mental Illness explains that if you have DID you might seem to have 2 or more different identities, called alternate identities, which might take control at different times. It says people used to call DID "multiple personality disorder", but that this is an outdated term. Your behaviour may change depending on which identity has control, and you might also have some difficulty remembering things that have happened as you switch between identities.

Rethink adds that there is some disagreement between researchers over the notion of DID. Some think people with DID have different identities, while others think these are different parts of one identity that are not working properly together. Those researchers suggest that DID is caused by experiencing severe trauma over a long time in childhood.

The NHS and Rethink Mental Illness describe several dissociative conditions that can look similar from the outside. The table below sets out how they differ.

The NHS says there are many possible causes, including previous traumatic experience. Someone with a dissociative disorder may have experienced physical, sexual or emotional abuse during childhood, and some people dissociate after war, kidnapping or even an invasive medical procedure. Switching off from reality is a normal defence mechanism during a traumatic time, the NHS explains, and it becomes a problem when the environment is no longer traumatic but the person still acts and lives as if it is, and has not processed the event.

People with a dissociative disorder may have other mental health conditions: medically unexplained symptoms, post-traumatic stress disorder (PTSD), depression, mood swings, anxiety and panic attacks, suicidal thoughts or self-harm, an eating disorder or obsessive compulsive disorder, and sleep problems. The NHS PTSD page lists feeling disconnected from yourself and the world around you (dissociation) as a recognised symptom of PTSD.

The NHS says a GP may examine you and do some tests to check whether another illness might be the cause of your symptoms, and may refer you to a mental health specialist for a full assessment. The specialist should have a good understanding of dissociative disorders.

The assessment may include questions about thoughts, feelings, behaviour and symptoms. The NHS stresses that it is important to be honest about symptoms and not to feel ashamed or embarrassed, so you can receive the help and support you need.

The NHS says many people with a dissociative disorder make a full recovery with treatment and support. Talking therapies such as counselling or psychotherapy are often recommended, with the aim of helping you cope with the underlying cause and to learn and practise techniques to manage periods of feeling disconnected.

Eye movement desensitisation and reprocessing (EMDR), a psychological treatment that can reduce symptoms of PTSD, is sometimes used to treat dissociative disorders. There is no specific medicine to treat dissociation, but medicines such as antidepressants may be prescribed to treat associated conditions like depression, anxiety and panic attacks.

For PTSD, which often co-occurs, the NHS lists trauma-focused CBT, EMDR and medicines, usually an antidepressant, as treatments, and says that if you are 18 or over you can refer yourself directly to an NHS talking therapies service.

Rethink Mental Illness says you will usually be offered talking therapies before medication. For DID, doctors may think about long-term, relationally based psychotherapy, in which you talk about your relationships and thoughts, and your therapist links the ways you think and act with things that have happened to you. It says psychotherapy might be needed for a long time, with at least 1 session every week.

Rethink also says that EMDR may help people with memories of trauma that affect them, but gives an important warning: before you have EMDR, ask the therapist to confirm that it has been specially adjusted for the treatment of dissociative disorders, because standard EMDR treatment is not suitable and could make you worse. It says parts of CBT are recommended for DID, to help change thoughts and behaviours that come from trauma.

Rethink notes that, at the time of writing, there are no NICE guidelines on dissociation or dissociative disorders, but this does not mean you should not be offered treatment. If you think you have a dissociative disorder, explain this to your GP, who may refer you to a psychiatrist.

Rethink Mental Illness says grounding techniques can help people who have been through trauma or who regularly dissociate, by anchoring you in the here and now. They work best when practised regularly, and not every technique works for everyone. Examples include focusing on 3 things you can see, 3 things you can hear and 3 things you can touch; describing your surroundings aloud or silently; using positive words; picturing a place that feels peaceful and safe; standing up, walking around or clapping your hands while breathing mindfully; and carrying a personal object with positive memories attached.

Rethink also says keeping a diary can help you notice what makes symptoms better or worse, and that you should talk to your GP or the person responsible for your care before changing how you manage things.

If you have thoughts about taking your life, the NHS says it is important to ask someone for help. You can speak to a friend, family member or someone you trust, call the Samaritans free 24-hour service, go to your nearest A&E, contact NHS 111 or make an urgent GP appointment.

Talking to your partner, family and friends about your experience can help them understand how you feel. The NHS names the charity Mind as a source of information on dissociative disorders and support organisations. If you are worried about someone else, the NHS suggests encouraging them to talk, listening without judging and avoiding offering solutions.

On the NHS, the route is usually through your GP to community mental health or psychological therapies services. Specialist trauma and dissociation services are limited, so waiting times and availability vary by area, and it may help to ask the referrer whether a clinician with experience of dissociative disorders will assess you.

Some people choose private psychiatric assessment or psychotherapy. It is worth checking that a therapist is registered with a recognised professional body and has experience of dissociation and trauma, and tell your GP so that your care stays coordinated and safe.