What Is Depersonalization Disorder?

  • Karl Jones BA Hons in Learning Disability Nursing, Diploma in Mental Health Nursing Oxford Brookes University
  • Chloe Vilenstein Master's degree, Neuroscience, Ecole normale supérieure, Paris, France
  • Olga Gabriel Master's degree, Forensic Science, Uppsala University, Sweden


Depersonalisation disorder and derealisation disorder (sometimes referred to as depersonalisation-derealisation disorder/syndrome) both fall under the umbrella of dissociative disorders. People who struggle with this disorder may feel a sense of disconnect from themselves and/or the external world. Many people experience fleeting symptoms of depersonalisation or derealisation disorder at some point in their lives that are not a cause for concern. However, for some, these symptoms are persistent or recurrent, which may be concerning and/or very distressing, heavily impacting their lives. This article will look at what the symptoms of depersonalisation/derealisation disorder are, their potential causes, how to seek help, and also assessment and treatment procedures. 

Causes of depersonalization disorder

Depersonalisation and derealisation may occur fleetingly in healthy individuals, especially in the context of fatigue, during or after alcohol or drug intoxication, or during brief, high-stress situations.

According to the International Classification of Diseases (ICD-10) manual by the World Health Organisation, depersonalisation/derealisation disorder symptoms may manifest as part of a diagnosable schizophrenic, depressive, phobic, or obsessive-compulsive disorder. There is no clear cause for depersonalisation/derealisation disorder. However, it is thought that there is a 20-40% increased chance of developing the disorder if someone has a pre-existing mental health condition. Whilst this is a relatively high chance, it does not mean that you will definitely experience symptoms of depersonalisation or derealisation.

There are studies suggesting that depersonalisation/derealisation disorder may be linked to a person experiencing previous trauma or intense/ongoing stress. These could include:

  • A parent with severe mental illness
  • Abuse (witnessing or experiencing it)
  • Accidents
  • Life-threatening danger
  • Natural disasters
  • Sudden death of a loved one
  • Violence
  • War

According to a paper by the American Psychiatric Association, symptoms may well begin in early childhood. It is said that the average age of onset is 16 years old, with only 20% of people experiencing the onset of these symptoms after the age of 20 years. 

Symptoms of depersonalisation/derealisation disorder have been linked to certain physical conditions. For instance, people experiencing epileptic seizures can display the same symptoms. More specifically, this would depend on the stage of the seizure (ictal or postictal).1 

Signs and symptoms of depersonalization disorder

Depersonalisation disorder symptoms may include:

  • Feeling detached from your body, mind, feelings, or sensations
  • Feeling like an outsider observing your life, like watching a film
  • Showing little to no emotion, with physical or emotional numbness
  • You may feel “unreal”, like a robot
  • You may also be unable to connect to your memories or be able to remember them clearly

Derealisation disorder symptoms may include:

  • Feeling detached from your surroundings, where everything seems unreal
  • You may feel like you’re in a dream
  • You may feel like you’re observing your surroundings through a fog or glass wall
  • Objects may appear blurry, distorted, or altered in size
  • Time may appear to move quicker or more slowly
  • Sounds may appear louder or quieter

Symptoms are almost always distressing, as, despite the altered perceptions of themselves or their world, people with depersonalization or derealisation are aware of their unreality. This awareness is indicated in the ICD-10 as one of the criteria for diagnosis.  

Management and treatment for depersonalization disorder

To date there are no guidelines for the treatment of depersonalisation produced by NICE (National Institute for Clinical Excellence) in the UK.2

The ICD-10 states that because depersonalisation/derealisation symptoms present as part of diagnosable schizophrenic, depressive, phobic, or obsessive-compulsive disorders, the main working diagnoses and treatment options would be influenced by those of the aforementioned disorders. This would likely include a combination of prescribed medication and talking therapy.

In conditions where there is a range of symptoms, it is important to focus on the symptoms experienced by the individual and look to alleviate those rather than seek a blanket treatment option that would work for everyone with the same diagnosis. The reason for this is that everyone’s experience of any given diagnosis may vary in intensity and severity of any number of symptoms.

It is generally recommended that the most appropriate treatment option for dissociative disorders such as depersonalisation/derealisation disorder is talking therapy; this could be counselling or psychological therapy such as cognitive behavioural therapy. Another talking therapy method that could be used is psychodynamic therapy, which looks at the underlying issues that impact thoughts and feelings.

Additionally, there are certain techniques such as grounding, which focuses on using your senses to help you feel more connected to the world around you, and behavioural strategies which can help with symptom management.3


How is depersonalization disorder diagnosed?

If you are experiencing symptoms described in this article, it is important to see your doctor to rule out any physical health condition. If there are no physical health reasons for your symptoms, then your health professional should be able to refer you for a comprehensive mental health assessment, which may examine your personal history, recent significant events, daily habits, and mental state. This may be conducted by a mental health nurse in the first instance, and you may then be referred to a psychiatrist to formulate a diagnosis and treatment plan. 

They may look at whether your symptoms have been recently triggered by stress, trauma, depression, or anxiety. Your symptoms will be cross-referenced with the diagnostic manual that is most commonly used in your country, and a treatment plan will be made based on national guidelines (in the UK, this would be NICE guidelines).

Can depersonalization disorder be prevented?

There is no clear cause of depersonalisation/derealisation disorder, and therefore no definitive way in which to prevent the disorder from occurring. It has been associated with depressive disorders and trauma responses, which one usually has no control over. As with many conditions/disorders, you can optimise your overall well-being by developing effective coping mechanisms, having a strong support network, keeping as healthy as possible in terms of diet, sleep, and reducing stress. You should seek help promptly if you have concerns. Although there is no definite way of preventing depersonalisation or derealisation disorder, you can work to reduce the risk of developing these disorders by managing possible triggers.

Who is at risk of depersonalization disorder?

Depersonalisation/derealisation disorder is not as well understood as many other mental health conditions. There is no evidence of a specific cause, and even predisposing factors do not necessarily mean that you will develop this disorder. Prevalence is fairly low in the general population (see below); however, it is significantly higher if you have a pre-existing mental health condition.

You may experience fleeting symptoms of depersonalisation/derealisation disorder as a result of fatigue or poor sleep, transient high-stress situations, and during and/or after alcohol or drug intoxication. Being fleeting, these brief symptoms do not qualify as a disorder.

You are at a higher risk of developing the disorder if you have a pre-existing depression, anxiety disorder or schizophrenia. Therefore, if you have a pre-existing mental health condition, it is important to optimise your mental well-being. This can be done by not consuming illicit drugs or excessive alcohol, getting enough sleep, taking medications that are prescribed by your doctor and generally looking after yourself. These strategies will reduce the chances of developing the disorder. 

How common is depersonalization disorder?

Transient or fleeting symptoms are common, and reasons for these fleeting symptoms can vary. It is thought that less than 2% of the general population have experienced a diagnosable depersonalisation or derealisation disorder. 

There is evidence that suggests that the prevalence in those with a pre-existing mental health condition is higher. In people with a diagnosed anxiety or depressive illness, about 20-40% of these people also experience depersonalisation/derealisation disorder symptoms.

When should I see a doctor?

Fleeting symptoms of depersonalisation or depersonalisation are common and are not necessarily associated with a serious physical or psychological condition. However, persistent or severe symptoms such as feelings of detachment or distortion of you or your surroundings may be an indication of depersonalisation/derealisation disorder or another mental health condition or physical health problem.

You should see your doctor or local mental health service if you have symptoms of depersonalisation or derealisation disorder that cause you to be concerned.

These could include:

  • Symptoms that are persistent or recurrent
  • Symptoms that cause emotional distress or disturb your thoughts
  • Or symptoms that negatively impact your daily life, such as work, relationships, or daily activities


Depersonalisation/derealisation disorder is a distressing disorder in which the individual experiences an altered perception or themselves and/or their world. It is particularly distressing because if you are experiencing the symptoms, then you are aware of your unreality. If left unchecked, your mental health could deteriorate and also lead to depression and anxiety.

It is fairly uncommon in the general population but significantly more prominent in people with pre-existing mental health conditions such as schizophrenia, depression, or anxiety disorders. This does not mean that if you have a mental health disorder, you are going to develop symptoms. If you have a pre-existing mental health condition, however, you must look after yourself to reduce the chances of developing the disorder.

Be mindful that it is fairly common for fleeting or transient symptoms to occur in the general population. This could be a result of poor sleep/fatigue, stress, or drug or alcohol intoxication. If you experience symptoms as a one-off, or they only occur as a result of drug or alcohol intoxication, then this does not meet the criteria for a diagnosis of the disorder.

In order to meet the criteria for a diagnosis of these disorders, you must experience some of the symptoms, as well as these symptoms being chronic or reoccurring.

If you suspect that you are experiencing symptoms that indicate a diagnosis of depersonalisation/derealisation disorder, then it is important that you see your doctor or mental health professional for further assessment and, if needed, treatment. 


  1. Heydrich L, Marillier G, Evans N, Seeck M, Blanke O. Depersonalization‐ and derealization‐like phenomena of epileptic origin. Ann Clin Transl Neurol [Internet]. 2019 Aug 22 [cited 2024 Jan 26];6(9):1739–47. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6764488/
  2. ICD-10 Version:2019 [Internet]. [cited 2024 Jan 26]. Available from: https://icd.who.int/browse10/2019/en#F48.0
  3. MSD Manual Professional Edition [Internet]. [cited 2024 Jan 26]. Dissociative amnesia - psychiatric disorders. Available from: https://www.msdmanuals.com/en-gb/professional/psychiatric-disorders/dissociative-disorders/dissociative-amnesia
  4. Cleveland Clinic [Internet]. [cited 2024 Jan 26]. Depersonalization-derealization disorder. Available from: https://my.clevelandclinic.org/health/diseases/9791-depersonalization-derealization-disorder
  5. Medford N, Sierra M, Baker D, David AS. Understanding and treating depersonalisation disorder. Advances in Psychiatric Treatment [Internet]. 2005 Mar [cited 2024 Jan 26];11(2):92–100. Available from: https://www.cambridge.org/core/journals/advances-in-psychiatric-treatment/article/understanding-and-treating-depersonalisation-disorder/6216AE06994D1094873145C016CC1F57
  6. MSD Manual Professional Edition [Internet]. [cited 2024 Jan 26]. Depersonalization/derealization disorder - psychiatric disorders. Available from: https://www.msdmanuals.com/en-gb/professional/psychiatric-disorders/dissociative-disorders/depersonalization-derealization-disorder
  7. What is a dissociative disorder (DID)? [Internet]. [cited 2024 Jan 26]. What is dissociation and dissociative identity disorder (Did)? Available from: https://www.rethink.org/advice-and-information/about-mental-illness/learn-more-about-conditions/dissociation-and-dissociative-identity-disorder-did/
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Karl Jones

BA Hons in Learning Disability Nursing, Diploma in Mental Health Nursing (Oxford Brookes

Karl has 12 years of experience in learning disability and mental health nursing in a variety of
settings. He has worked predominantly in general hospitals specialising in suicide prevention and the
psychological impact on long term health conditions. Most recently he has worked as a clinical
educator in the field of mental health. He is currently focusing on writing as a career with the aim of
imparting his knowledge to a wider audience.

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