Depersonalization-derealization disorder

Depersonalization-derealization disorder (DPDR, DDD)^[3][4] is a mental disorder in which the person has persistent or recurrent feelings of depersonalization and/or derealization. Depersonalization is described as feeling disconnected or detached from one's self. Individuals may report feeling as if they are an outside observer of their own thoughts or body, and often report feeling a loss of control over their thoughts or actions.^[5] Derealization is described as detachment from one's surroundings. Individuals experiencing derealization may report perceiving the world around them as foggy, dreamlike, surreal, and/or visually distorted.^[5]

Depersonalization-derealization disorder
Other names	Depersonalization disorder, derealization disorder
Specialty	Psychiatry, clinical psychology
Symptoms	Feeling detached from oneself (depersonalization), feeling detached from one's surroundings (derealization)
Usual onset	Adolescence
Duration	Episodic, chronic
Risk factors	childhood trauma, substance use
Treatment	Psychotherapy
Prognosis	Usually positive^[1]
Frequency	1–2% (general population)^[2]

Depersonalization-derealization disorder is thought to be caused largely by interpersonal trauma such as early childhood abuse.^[6][7] Adverse early childhood experiences, specifically emotional abuse and neglect have been linked to the development of depersonalization symptoms.^[8] Feelings of depersonalization and derealization are common from significant stress or panic attacks.^[6] Individuals may remain in a depersonalized state for the duration of a typical panic attack. However, in some cases, the dissociated state may last for hours, days, weeks, or even months at a time.^[9] In rare cases, symptoms of a single episode can last for years.^[10]

Diagnostic criteria for depersonalization-derealization disorder includes persistent or recurrent feelings of detachment from one's mental or bodily processes or from one's surroundings.^[11] A diagnosis is made when the dissociation is persistent, interferes with the social or occupational functions of daily life, and/or causes marked distress in the patient.^[3]

While depersonalization-derealization disorder was once considered rare, lifetime experiences with it occur in about 1–2% of the general population.^[12] The chronic form of the disorder has a reported prevalence of 0.8 to 1.9%.^[13][14] While brief episodes of depersonalization or derealization can be common in the general population, the disorder is only diagnosed when these symptoms cause substantial distress or impair social, occupational, or other important areas of functioning.^[15]

Signs and symptoms

The core symptoms of depersonalization-derealization disorder are the subjective experience of "unreality in one's self",^[16] or detachment from one's surroundings. People who are diagnosed with depersonalization also often experience an urge to question and think critically about the nature of reality and existence.^[15]

Individuals with depersonalization describe feeling disconnected from their physicality; feeling as if they are not completely occupying their own body; feeling as if their speech or physical movements are out of their control; feeling detached from their own thoughts or emotions; and experiencing themselves and their lives from a distance.^[17][18] While depersonalization involves detachment from one's self, individuals with derealization feel detached from their surroundings, as if the world around them is foggy, dreamlike, or visually distorted. Individuals with the disorder commonly describe a feeling as though time is passing them by and they are not in the notion of the present. In some cases, individuals may be unable to accept their reflection as their own, or they may have out-of-body experiences.^[17] Additionally some individuals experience difficulty concentrating and problems with memory retrieval. These individuals sometimes lack the "feeling" of a memory where they are able to recall a memory but feel as if they did not personally experience it.^[19][20] These experiences which strike at the core of a person's identity and consciousness may cause a person to feel uneasy or anxious.^[15] The inner turmoil created by the disorder can also result in depression.^[21]

First experiences with depersonalization may be frightening, with patients fearing loss of control, dissociation from the rest of society and functional impairment.^[14] The majority of people with depersonalization-derealization disorder misinterpret the symptoms, thinking that they are signs of serious psychosis or brain dysfunction. This commonly leads to an increase of anxiety and obsession, which contributes to the worsening of symptoms.^[22]

Factors that tend to diminish symptoms are comforting personal interactions, intense physical or emotional stimulation, and relaxation.^[23] Distracting oneself (by engaging in conversation or watching a movie, for example) may also provide temporary relief. Some other factors that are identified as relieving symptom severity are diet or exercise, while alcohol and fatigue are listed by some as worsening their symptoms.^[24]

Occasional, brief moments of mild depersonalization can be experienced by many members of the general population;^[25] however, depersonalization-derealization disorder occurs when these feelings are strong, severe, persistent, or recurrent and when these feelings interfere with daily functioning.^[21] DPDR is most commonly experienced as chronic and continuous. However, for a minority who have DPDR as an episodic condition, duration of these episodes is highly variable with some lasting as long as several weeks.^[26][27]

Causes

The exact cause of depersonalization is unknown, although biopsychosocial correlations and triggers have been identified. It has been thought that depersonalization can be caused by a biological response to dangerous or life-threatening situations which causes heightened senses and emotional numbing.^[14]

Psychosocial

There is growing evidence linking physical and sexual abuse in childhood with the development of dissociative disorders.^[26] Childhood interpersonal trauma – emotional abuse in particular – is a significant predictor of a diagnosis of DPDR.^[28] Compared to other types of childhood trauma, emotional abuse has been found to be the most significant predictor both of a diagnosis of depersonalization disorder and of depersonalization scores, but not of general dissociation scores.^[29] Some studies suggest that greater emotional abuse and lower physical abuse predict depersonalization in adult women with post-traumatic stress disorder (PTSD).^[30] Patients with high interpersonal abuse histories (HIA) show significantly higher scores on the Cambridge Depersonalization Scale, when compared to a control group.^[31][8] Earlier age of abuse, increased duration and parental abuse tend to correlate with severity of dissociative symptoms.^[26][32] Besides traumatic experiences, other common precipitators of the disorder include severe stress, major depressive disorder or panic attacks.^[33] People who live in highly individualistic cultures may be more vulnerable to depersonalization due to a hypersensitivity towards threats and fears of losing control.^[34]

A 2010 study^[35] found evidence that some users participating in virtual reality (VR) may be more likely to experience dissociation after use. Users reportedly experienced higher levels of a lessened sense of presence in reality after exposure to VR. However, it was noted that the effects of exposure were likely to rapidly disappear after returning to objective reality. Additionally, individuals who reported higher preexisting dissociation levels as well being more easily immersed or absorbed in imagination overall were found to be linked to higher increases in dissociative symptoms after the VR exposure. This study offered evidence towards a link between imaginative processes of the brain and dissociative experiences.

Neurobiology

 

Animated image showing prefrontal cortex, which is thought to play a role in DPDR

There is converging evidence that the prefrontal cortex may inhibit neural circuits that normally form the basis of emotional experience.^[36] In an fMRI study of DPDR patients, emotionally aversive scenes activated the right ventral prefrontal cortex. Participants demonstrated a reduced neural response in emotion-sensitive regions, as well as an increased response in regions associated with emotional regulation.^[37] In a similar test of emotional memory, depersonalization disorder patients did not process emotionally salient material in the same way as did healthy controls.^[38] In a test of skin conductance responses to unpleasant stimuli, the subjects showed a selective inhibitory mechanism on emotional processing.^[39]

Studies are beginning to show that the temporoparietal junction has a role in multisensory integration, embodiment, and self-other distinction.^[40] Several studies analyzing brain MRI findings from DPDR patients found decreased cortical thickness in the right middle temporal gyrus, reduction in grey matter volume in the right caudate, thalamus, and occipital gyri, as well as lower white matter integrity in the left temporal and right temporoparietal regions. However, no structural changes in the amygdala were observed.^[41][42][43]

A PET scan found functional abnormalities in the visual, auditory, and somatosensory cortex, as well as in areas responsible for an integrated body schema.^[44]

One study examining EEG readings found frontal alpha wave overactivation and increased theta activity waves in the temporal region of the left hemisphere.^[45]

 

Image showing temporoparietal junction, a portion of the brain also thought to play a role in DPDR

It is unclear whether genetics plays a role; however, there are many neurochemical and hormonal changes in individuals with depersonalization disorder.^[6] DPDR may be associated with dysregulation of the hypothalamic-pituitary-adrenal axis, the area of the brain involved in the "fight-or-flight" response. Patients demonstrate abnormal cortisol levels and basal activity. Studies found that patients with DPDR could be distinguished from patients with clinical depression and posttraumatic stress disorder.^[46][47]

The vestibular system may also play a role in DPDR. The vestibular system helps control balance, spatial orientation, motor coordination, but also plays a role in self-awareness. Disruption to this system can potentially cause a feeling of detachment from surroundings. Several studies have shown that patients with peripheral vestibular disease are also more likely to have dissociative symptoms when compared to healthy individuals.^[48]

Dissociative symptoms are sometimes described by those with neurological diseases, such as amyotrophic lateral sclerosis, Alzheimer's, multiple sclerosis (MS), etc., that directly affect brain tissue.^[49]

Diagnosis

Assessment

Diagnosis is based on the self-reported experiences of the person followed by a clinical assessment. Psychiatric assessment includes a psychiatric history and some form of mental status examination. Since some medical and psychiatric conditions mimic the symptoms of DPDR, clinicians must differentiate between and rule out the following to establish a precise diagnosis: temporal lobe epilepsy, panic disorder, acute stress disorder, schizophrenia, migraine, drug use, brain tumor or lesion.^[17] No laboratory test for depersonalization-derealization disorder currently exists.^[11] As patients with dissociative disorders likely experienced intense trauma in the past, concomitant dissociative disorders should be considered in patients diagnosed with a stress disorder (i.e. PTSD or acute stress disorder).^[50]

The diagnosis of depersonalization disorder can be made with the use of the following interviews and scales:

• The Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D) is widely used, especially in research settings. This interview takes about 30 minutes to 1.5 hours, depending on individual's experiences.^[51]

• The Dissociative Experiences Scale (DES) is a simple, quick, self-administered questionnaire that has been widely used to measure dissociative symptoms.^[52] It has been used in hundreds of dissociative studies, and can detect depersonalization and derealization experiences.^[53]
• The Dissociative Disorders Interview Schedule (DDIS) is a highly structured interview which makes DSM-IV diagnoses of somatization disorder, borderline personality disorder and major depressive disorder, as well as all the dissociative disorders.^[54] It inquires about positive symptoms of schizophrenia, secondary features of dissociative identity disorder, extrasensory experiences, substance abuse and other items relevant to the dissociative disorders. The DDIS can usually be administered in 30–45 minutes.^[54]
• The Cambridge Depersonalization Scale (CDS) is a method for determining the severity of depersonalization disorder. It has been proven and accepted as a valid tool for the diagnosis of depersonalization disorder in a clinical setting. It is also used in a clinical setting to differentiate minor episodes of depersonalization from actual symptoms of the disorder. Due to the success of the CDS, a group of Japanese researchers underwent the effort to translate the CDS into the J-CDS or the Japanese Cambridge Depersonalization Scale. Through clinical trials, the Japanese research team successfully tested their scale and determined its accuracy. One limitation is that the scale does not allow for the differentiation between past and present episodes of depersonalization. It may be difficult for the individual to describe the duration of a depersonalization episode, and thus the scale may lack accuracy. The project was conducted in the hope that it would stimulate further scientific investigations into depersonalization disorder.^[55]

Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5)

In the DSM-5, the word "derealization" was added to "depersonalization disorder" and renamed "depersonalization/derealization disorder" ("DPDR").^[3] It remains classified as a dissociative disorder.^[3]

Patients must meet the following criteria to be diagnosed per the DSM-5:^[3]

1. Presence of persistent/recurrent episodes of depersonalization/derealization
2. Ability to distinguish between reality and dissociation during an episode (i.e. patient is aware of a perceptual disturbance)
3. Symptoms are severe enough to interfere with social, occupational, or other areas of functioning
4. Symptoms are not due to a substance or medication
5. Symptoms are not due to another psychiatric disorder

International Classification of Diseases 11th Revision (ICD-11)

The ICD-11 has relisted DPDR as a disorder rather than a syndrome as previously, and has also reclassified it as a dissociative disorder from its previous listing as a neurotic disorder.^[4] The description used in the ICD-11 is similar to the criteria found in the DSM-5. Individuals with DPDR are described as having persistent/recurrent symptoms of depersonalization/derealization, have intact reality testing, and symptoms are not better explained by another psychiatric/neural disorder, substance, medication, or head trauma. Symptoms are severe enough to cause distress or impairment in functioning.^[56]

Differential diagnoses

DPDR differentials include neurologic and psychiatric conditions as well as side effects from psychoactive substances or medications.^[12][57]

Neurologic

• Seizures
• Brain tumor
• Post-concussion syndrome
• Metabolic abnormalities
• Migraines
• Vertigo
• Meniere's disease
• Visual snow syndrome

Psychiatric

• Panic attack
• Phobias
• Post-traumatic stress disorder
• Acute stress disorder
• Depression
• Bipolar disorder
• Schizophrenia
• Borderline personality disorder
• Other dissociative disorders
  • Dissociative identity disorder

Consequence of psychoactive substance use

• Marijuana
• Hallucinogens
• MDMA
• Ketamine
• Hallucinogen persisting perception disorder

Prevention

Depersonalization-derealization disorder may be prevented by connecting children who have been abused with professional mental health help.^[58][59] Some trauma specialists strongly advocate for increasing inquiry into information about children's trauma history and exposure to violence, since the majority of people (about 80%) responsible for child maltreatment are the child's own caregivers.^[60] Trauma-specific intervention for children may be useful in preventing future symptoms.^[61]

Treatment

Treatment of DPDR is often difficult and refractory. Some clinicians speculate that this could be due to a delay in diagnosis by which point symptoms tend to be constant and less responsive to treatment.^[12] Additionally, symptoms tend to overlap with other diagnoses.^[48] Some results have been promising, but are hard to evaluate with confidence due to the small size of trials.^[62] However, recognizing and diagnosing the condition may in itself have therapeutic benefits, considering many patients express their problems as baffling and unique to them, but are not, in fact, and are recognized and described by psychiatry.^[63] However, symptoms are often transient and can remit on their own without treatment.^[26]

Treatment is primarily pharmacological.^[64] Self-hypnosis training can be helpful and entails training patients to induce dissociative symptoms and respond in an alternative manner.^[65] Psychoeducation involves counseling regarding the disorder, reassurance, and emphasis on DPDR as a perceptual disturbance rather than a true physical experience.^[12] Clinical pharmacotherapy research continues to explore a number of possible options, including selective serotonin reuptake inhibitors (SSRI), benzodiazepines, stimulants and opioid antagonists (ex: naltrexone).^[12]

Cognitive behavioral therapy

An open study of cognitive behavioral therapy has aimed to help patients reinterpret their symptoms in a nonthreatening way, leading to an improvement on several standardized measures.^[64] A standardized treatment for DPDR based on cognitive behavioral principles was published in the Netherlands in 2011.^[66]

Medications

Tentative evidence supports the use of opioid antagonists (naloxone) and other medications like benzodiazepines or methylphenidate. Evidence suggests the beneficial use of lamotrigine adjunct to an SSRI but not as monotherapy. ^[64]

A combination of an SSRI and a benzodiazepine has been proposed to be useful for DPDR patients with anxiety.^[67]

Modafinil used alone has been reported to be effective in a subgroup of individuals with depersonalization disorder (those who have attentional impairments, under-arousal and hypersomnia). However, clinical trials have not been conducted.^[68]

Repetitive transcranial magnetic stimulation (rTMS)

Some studies have found repetitive transcranial magnetic stimulation (rTMS) to be helpful.^[69][70][71] One study examined 12 patients with DPDR that were treated with right temporoparietal junction (TPJ) rTMS and found that 50% showed improvement after three weeks of treatment. Five of the participants received an additional three weeks of treatment and reported overall a 68% improvement in their symptoms.^[69] Treating patients with rTMS specifically at the TPJ may be an alternative treatment.^[69]

Prognosis

Michal et al. (2016) analyzed a case series on 223 patients suffering from DPDR and agreed that the condition tended to be long-lasting.^[72] However, while no medication has been confirmed to successfully treat the condition, psychotherapy might help. In some cases, recovery can take place organically, without formal treatment.^[73]

Epidemiology

Men and women are diagnosed in equal numbers with depersonalization disorder.^[24] A 1991 study on a sample from Winnipeg, Manitoba estimated the prevalence of depersonalization disorder at 2.4% of the population.^[74] A 2008 review of several studies estimated the prevalence between 0.8% and 1.9%.^[67] This disorder is episodic in only one-third of individuals,^[24] with each episode lasting from hours to months at a time. Depersonalization can begin episodically, and later become continuous at constant or varying intensity.^[24]

Onset is typically during adolescence, although some patients report being depersonalized as long as they can remember, and a small minority report a later onset (by age 40).^[23][24] According to the DSM-5-TR, less than 20% of patients with the disorder first experience symptoms after age 20 years; 80% or more have their onset in the first 2 decades of life - childhood and adolescence. The onset can be acute or insidious in nature. With acute onset, some individuals remember the exact time and place of their first experience of depersonalization and/or derealization. This may follow a prolonged period of severe stress, a traumatic event, or an episode of another mental illness.^[24] Insidious onset may reach back as far as can be remembered (early childhood), or it may begin with smaller episodes of lesser severity that become gradually more intense and more disabling. Some patients report persistent depersonalization and/or derealization throughout the day, nearly everyday.

Relation to other psychiatric disorders

Depersonalization exists as both a primary and secondary phenomenon.^[75] The most common comorbid disorders are depression and anxiety,^[15] although cases of depersonalization disorder without symptoms of either do exist. Comorbid obsessive/compulsive behaviors may exist as attempts to deal with depersonalization, such as checking whether symptoms have changed and avoiding behavioral and cognitive factors that exacerbate symptoms. Many people with personality disorders such as schizoid personality disorder, schizotypal personality disorder, and borderline personality disorder will have experiences of depersonalization. Patients with complex dissociative disorders, including dissociative identity disorder, experience high levels of depersonalization and derealization.^[76]

History

The word depersonalization itself was first used by Henri Frédéric Amiel in The Journal Intime. The 8 July 1880 entry reads:

I find myself regarding existence as though from beyond the tomb, from another world; all is strange to me; I am, as it were, outside my own body and individuality; I am depersonalized, detached, cut adrift. Is this madness?^[77]

Depersonalization was first used as a clinical term by Ludovic Dugas in 1898 to refer to "a state in which there is the feeling or sensation that thoughts and acts elude the self and become strange; there is an alienation of personality – in other words a depersonalization". This description refers to personalization as a psychical synthesis of attribution of states to the self.^[78]

Early theories of the cause of depersonalization focused on sensory impairment. Maurice Krishaber proposed depersonalization was the result of pathological changes to the body's sensory modalities which lead to experiences of "self-strangeness" and the description of one patient who "feels that he is no longer himself". One of Carl Wernicke's students suggested all sensations were composed of a sensory component and a related muscular sensation that came from the movement itself and served to guide the sensory apparatus to the stimulus. In depersonalized patients, these two components were not synchronized, and the myogenic sensation failed to reach consciousness. The sensory hypothesis was challenged by others who suggested that patient complaints were being taken too literally and that some descriptions were metaphors – attempts to describe experiences that are difficult to articulate in words. Pierre Janet approached the theory by pointing out his patients with clear sensory pathology did not complain of symptoms of unreality, and that those who have depersonalization were normal from a sensory viewpoint.^[78]

Psychodynamic theory formed the basis for the conceptualization of dissociation as a defense mechanism. Within this framework, depersonalization is understood as a defense against a variety of negative feelings, conflicts, or experiences. Sigmund Freud himself experienced fleeting derealization when visiting the Acropolis in person; having read about it for years and knowing it existed, seeing the real thing was overwhelming and proved difficult for him to perceive it as real.^[79] Freudian theory is the basis for the description of depersonalization as a dissociative reaction, placed within the category of psychoneurotic disorders, in the first two editions of the Diagnostic and Statistical Manual of Mental Disorders.^[80]

It can be argued that because depersonalization and derealization are both impairments to one's ability to perceive reality, they are merely two facets of the same disorder. Depersonalization also differs from delusion in the sense that the patient is able to differentiate between reality and the symptoms they may experience. The ability to sense that something is unreal is maintained when experiencing symptoms of the disorder. The problem with properly defining depersonalization also lies within the understanding of what reality actually is.^[81] In order to comprehend the nature of reality we must incorporate all the subjective experiences throughout and thus the problem of obtaining an objective definition is brought about again.^[82]

Society and culture

Depersonalization disorder has appeared in a variety of media. The director of the autobiographical documentary Tarnation, Jonathan Caouette, had depersonalization disorder. The screenwriter for the 2007 film Numb had depersonalization disorder, as does the film's protagonist played by Matthew Perry. Norwegian painter Edvard Munch's famous masterpiece The Scream may have been inspired by depersonalization disorder.^[83] In Glen Hirshberg's novel The Snowman's Children, main female plot characters throughout the book had a condition that is revealed to be depersonalization disorder.^[84] Suzanne Segal had an episode in her 20s that was diagnosed by several psychologists as depersonalization disorder, though Segal herself interpreted it through the lens of Buddhism as a spiritual experience, commonly known as "Satori" or "Samadhi".^[85] The song "Is Happiness Just a Word?" by hip hop artist Vinnie Paz describes his struggle with depersonalization disorder. Adam Duritz, of the band Counting Crows, has often spoken about his diagnosis of depersonalization disorder.^[86]

See also

• Anosognosia
• Self-disorder
• Cotard's syndrome
• Solipsism syndrome

References

1. "Depersonalization/Derealization Disorder". from the original on 28 January 2024. Retrieved 28 January 2024.
2. Hunter, EC; Sierra, M; David, AS (January 2004). "The epidemiology of depersonalisation and derealisation. A systematic review". Social Psychiatry and Psychiatric Epidemiology. 39 (1): 9–18. doi:10.1007/s00127-004-0701-4. PMID 15022041. S2CID 31285190.
3. Diagnostic and statistical manual of mental disorders : DSM-5 (5th ed.). Arlington, VA: American Psychiatric Association. 2013. pp. 302–306. ISBN 9780890425541.
4. "ICD-11 - Mortality and Morbidity Statistics". icd.who.int. Archived from the original on 1 August 2018. Retrieved 15 September 2020.
5. "Depersonalization derealization disorder: Epidemiology, pathogenesis, clinical manifestations, course, and diagnosis". from the original on 18 May 2015.
6. Simeon, D (2004). "Depersonalisation disorder: a contemporary overview". CNS Drugs. 18 (6): 343–54. doi:10.2165/00023210-200418060-00002. PMID 15089102. S2CID 18506672.
7. Simeon, Daphne; Guralnik, Orna; Schmeidler, James; Sirof, Beth; Knutelska, Margaret (July 2001). "The Role of Childhood Interpersonal Trauma in Depersonalization Disorder". American Journal of Psychiatry. 158 (7): 1027–1033. doi:10.1176/appi.ajp.158.7.1027. ISSN 0002-953X. PMID 11431223. from the original on 11 May 2024. Retrieved 11 May 2024.
8. Thomson, Paula; Jaque, S. Victoria (15 March 2018). "Depersonalization, adversity, emotionality, and coping with stressful situations". Journal of Trauma & Dissociation. 19 (2): 143–161. doi:10.1080/15299732.2017.1329770. ISSN 1529-9732. PMID 28509616. S2CID 3431258. from the original on 26 January 2024. Retrieved 11 December 2020.
9. "Depersonalization-derealization disorder - Symptoms and causes". Mayo Clinic. from the original on 8 October 2017. Retrieved 25 January 2024.
10. Sierra, Mauricio (1 January 2008). "Depersonalization disorder: pharmacological approaches". Expert Review of Neurotherapeutics. 8 (1): 19–26. doi:10.1586/14737175.8.1.19. ISSN 1473-7175. PMID 18088198. S2CID 22180718. from the original on 29 May 2020. Retrieved 27 October 2022.
11. Depersonalization Disorder, (DSM-IV 300.6, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition)
12. Sadock, Benjamin J.; Sadock, Virginia A.; Ruiz, Pedro (11 May 2017). Kaplan & Sadock's comprehensive textbook of psychiatry (Tenth ed.). Philadelphia: Wolters Kluwer. ISBN 978-1-4963-8915-2. OCLC 988106757.
13. Hürlimann, F; Kupferschmid, S; Simon, AE (2012). "Cannabis-induced depersonalization disorder in adolescence". Neuropsychobiology. 65 (3): 141–6. doi:10.1159/000334605. PMID 22378193. S2CID 30668662. Although depersonalization disorder has a low prevalence, with a reported prevalence ranging from 0.8 to 1.9%
14. Blevins, Christy A.; Weathers, Frank W.; Mason, Elizabeth A. (1 October 2012). "Construct Validity of Three Depersonalization Measures in Trauma-Exposed College Students". Journal of Trauma & Dissociation. 13 (5): 539–553. doi:10.1080/15299732.2012.678470. PMID 22989242. S2CID 9683966.
15. Sierra, Mauricio; Medford, Nick; Wyatt, Geddes; David, Anthony S. (1 May 2012). "Depersonalization disorder and anxiety: A special relationship?". Psychiatry Research. 197 (1–2): 123–127. doi:10.1016/j.psychres.2011.12.017. PMID 22414660. S2CID 7108552.
16. Radovic F (2002). "Feelings of Unreality: A Conceptual and Phenomenological Analysis of the Language of Depersonalization". Philosophy, Psychiatry, & Psychology. 9 (3): 9: 271–279. doi:10.1353/ppp.2003.0048. S2CID 145074433.
17. Simeon D (2004). "Depersonalisation Disorder: A Contemporary Overview". CNS Drugs. 18 (6): 343–354. doi:10.2165/00023210-200418060-00002. PMID 15089102. S2CID 18506672.
18. Radovic, Filip; Radovic, Susanna (September 2002). "Feelings of Unreality: A Conceptual and Phenomenological Analysis of the Language of Depersonalization". Philosophy, Psychiatry, & Psychology. 9 (3): 271–279. doi:10.1353/ppp.2003.0048. ISSN 1086-3303. from the original on 6 May 2024. Retrieved 11 May 2024.
19. Lambert, M. V.; Senior, C.; Fewtrell, W. D.; Phillips, M. L.; David, A. S. (March 2001). "Primary and secondary depersonalisation disorder: a psychometric study". Journal of Affective Disorders. 63 (1–3): 249–256. doi:10.1016/s0165-0327(00)00197-x. ISSN 0165-0327. PMID 11246104. from the original on 2 November 2020. Retrieved 27 October 2020.
20. Sierra, Mauricio; David, Anthony S. (March 2011). "Depersonalization: a selective impairment of self-awareness". Consciousness and Cognition. 20 (1): 99–108. doi:10.1016/j.concog.2010.10.018. ISSN 1090-2376. PMID 21087873. S2CID 17211680. from the original on 31 October 2020. Retrieved 27 October 2020.
21. "Symptoms and causes - Mayo Clinic". www.mayoclinic.org. from the original on 10 October 2019. Retrieved 20 November 2019.
22. Sacco, Robert G. (December 2010). "The Circumplex Structure of Depersonalization/Derealization". International Journal of Psychological Studies. 2 (2): 26–40. doi:10.5539/ijps.v2n2p26.
23. Simeon D, Knutelska M, Nelson D, Guralnik O (2003). "Feeling unreal: a depersonalization disorder update of 117 cases". Journal of Clinical Psychiatry. 64 (9): 990–7. doi:10.4088/JCP.v64n0903. PMID 14628973.
24. Baker D, Hunter E, Lawrence E, et al. (May 2003). "Depersonalisation disorder: clinical features of 204 cases". The British Journal of Psychiatry. 182 (5): 428–33. doi:10.1192/bjp.182.5.428. PMID 12724246.
25. Daphne Simeon; Jeffrey Abugel (7 November 2008). Feeling Unreal: Depersonalization Disorder and the Loss of the Self. Oxford University Press. p. 3. ISBN 978-0-19-976635-2. from the original on 1 August 2020. Retrieved 17 November 2016.
26. Roberts, Laura Weiss, ed. (2 May 2019). The American Psychiatric Association Publishing textbook of psychiatry (Seventh ed.). Washington, D.C.: American Psychiatric Association Publishing. ISBN 978-1-61537-256-0. OCLC 1090279671.
27. Black, Donald W.; Andreasen, Nancy C. (2014). Introductory textbook of psychiatry (Sixth ed.). Washington, DC: American Psychiatric Publishing. ISBN 978-1-58562-469-0. OCLC 865641999.
28. Simeon D, Guralnik O, Schmeidler J, Sirof B, Knutelska M (2001). "The role of childhood interpersonal trauma in depersonalization disorder". The American Journal of Psychiatry. 158 (7): 1027–33. doi:10.1176/appi.ajp.158.7.1027. PMID 11431223.
29. Simeon, D.; Guralnik, O.; Schmeidler, J.; Sirof, B.; Knutelska, M. (July 2001). "The role of childhood interpersonal trauma in depersonalization disorder". The American Journal of Psychiatry. 158 (7): 1027–1033. doi:10.1176/appi.ajp.158.7.1027. ISSN 0002-953X. PMID 11431223. from the original on 11 November 2020. Retrieved 11 December 2020.
30. King, Christopher D.; Hill, Sarah B.; Wolff, Jonathan D.; Bigony, Cara E.; Winternitz, Sherry; Ressler, Kerry J.; Kaufman, Milissa L.; Lebois, Lauren A. M. (1 October 2020). "Childhood maltreatment type and severity predict depersonalization and derealization in treatment-seeking women with posttraumatic stress disorder". Psychiatry Research. 292: 113301. doi:10.1016/j.psychres.2020.113301. ISSN 0165-1781. PMC 8217993. PMID 32736266. S2CID 220602831.
31. Aponte-Soto, Michell; Martinez-Taboas, Alfonso; Vélez-Pastrana, María C.; González, Rafael A. (28 June 2019). "The Relationship between Interpersonal Abuse and Depersonalization Experiences". Revista Puertorriqueña de Psicología. 30 (1): 48–59. from the original on 11 May 2024. Retrieved 11 May 2024.
32. Vonderlin, Ruben; Kleindienst, Nikolaus; Alpers, Georg W.; Bohus, Martin; Lyssenko, Lisa; Schmahl, Christian (November 2018). "Dissociation in victims of childhood abuse or neglect: a meta-analytic review". Psychological Medicine. 48 (15): 2467–2476. doi:10.1017/S0033291718000740. ISSN 0033-2917. PMID 29631646. S2CID 4731143. from the original on 26 April 2021. Retrieved 11 December 2020.
33. Simeon D: Depersonalisation disorder: a contemporary overview 22 April 2007 at the Wayback Machine. CNS Drugs. 2004.
34. Sierra-Siegert M, David AS (December 2007). "Depersonalization and individualism: the effect of culture on symptom profiles in panic disorder". J. Nerv. Ment. Dis. 195 (12): 989–95. doi:10.1097/NMD.0b013e31815c19f7. PMID 18091192. S2CID 7182322.
35. Aardema, F.; O'Connor, K.; Côté, S.; Taillon, A. (2010). "Virtual reality induces dissociation and lowers sense of presence in objective reality". Cyberpsychology, Behavior and Social Networking. 13 (4): 429–435. doi:10.1089/cyber.2009.0164. PMID 20712501. from the original on 25 April 2021. Retrieved 20 March 2021.
36. Medford N, Sierra M, Baker D, David A (2005). "Understanding and treating depersonalisation disorder". Advances in Psychiatric Treatment. 11 (2): 92–100. doi:10.1192/apt.11.2.92. from the original on 16 July 2011.
37. Phillips ML, Medford N, Senior C, Bullmore ET, Suckling J, Brammer MJ, Andrew C, Sierra M, Williams SC, et al. (2001). "Depersonalization disorder: thinking without feeling". Psychiatry Research: Neuroimaging. 108 (3): 145–160. doi:10.1016/S0925-4927(01)00119-6. PMID 11756013. S2CID 17628471.
38. Medford N, Brierley B, Brammer M, Bullmore ET, David AS, Phillips ML (December 2006). (PDF). Psychiatry Research: Neuroimaging. 148 (2–3): 93–102. doi:10.1016/j.pscychresns.2006.05.007. PMID 17085021. S2CID 8050125. Archived from the original (PDF) on 26 September 2007.
39. Sierra M, Senior C, Dalton J, et al. (September 2002). "Autonomic response in depersonalization disorder". Archives of General Psychiatry. 59 (9): 833–8. doi:10.1001/archpsyc.59.9.833. PMID 12215083.
40. Eddy, Clare M. (1 August 2016). "The junction between self and other? Temporo-parietal dysfunction in neuropsychiatry". Neuropsychologia. 89: 465–477. doi:10.1016/j.neuropsychologia.2016.07.030. ISSN 0028-3932. PMID 27457686. S2CID 3264331.
41. Sierra, Mauricio; Nestler, Steffen; Jay, Emma-Louise; Ecker, Christine; Feng, Yue; David, Anthony S. (30 October 2014). "A structural MRI study of cortical thickness in depersonalisation disorder". Psychiatry Research. 224 (1): 1–7. doi:10.1016/j.pscychresns.2014.06.007. ISSN 1872-7123. PMID 25089021. S2CID 9510592. from the original on 2 November 2020. Retrieved 27 October 2020.
42. Sierk, A.; Daniels, J. K.; Manthey, A.; Kok, J. G.; Leemans, A.; Gaebler, M.; Lamke, J. P.; Kruschwitz, J.; Walter, H. (2018). "White matter network alterations in patients with depersonalization/derealization disorder – Journal of Psychiatry & Neuroscience". Journal of Psychiatry & Neuroscience. 43 (5): 347–357. doi:10.1503/jpn.170110. PMC 6158023. PMID 30125247. from the original on 24 October 2020. Retrieved 27 October 2020.
43. Daniels, J. K.; Gaebler, M.; Lamke, J. P.; Walter, H. (2015). "Grey matter alterations in patients with depersonalization disorder: a voxel-based morphometry study – Journal of Psychiatry & Neuroscience". Journal of Psychiatry & Neuroscience. 40 (1): 19–27. doi:10.1503/jpn.130284. PMC 4275327. PMID 25285875. from the original on 24 October 2020. Retrieved 27 October 2020.
44. Simeon D, Guralnik O, Hazlett EA, Spiegel-Cohen J, Hollander E, Buchsbaum MS (November 2000). "Feeling unreal: a PET study of depersonalization disorder". The American Journal of Psychiatry. 157 (11): 1782–8. doi:10.1176/appi.ajp.157.11.1782. PMID 11058475.
45. Hollander, Eric; Carrasco, Jose L.; Mullen, Linda S.; Trungold, Sari; DeCaria, Concetta M.; Towey, James (June 1992). "Left hemispheric activation in depersonalization disorder: A case report". Biological Psychiatry. 31 (11): 1157–1162. doi:10.1016/0006-3223(92)90161-r. ISSN 0006-3223. PMID 1525279. S2CID 40775819.
46. Simeon D, Guralnik O, Knutelska M, Hollander E, Schmeidler J (2001). "Hypothalamic-pituitary-adrenal axis dysregulation in depersonalization disorder". Neuropsychopharmacology. 25 (5): 793–5. doi:10.1016/S0893-133X(01)00288-3. PMID 11682263.
47. Stanton BR, David AS, Cleare AJ, et al. (2001). "Basal activity of the hypothalamic-pituitary-adrenal axis in patients with depersonalization disorder". Psychiatry Research. 104 (1): 85–9. doi:10.1016/S0165-1781(01)00291-8. PMID 11600192. S2CID 13507830.
48. Salami, Abbas; Andreu-Perez, Javier; Gillmeister, Helge (1 November 2020). "Symptoms of depersonalisation/derealisation disorder as measured by brain electrical activity: A systematic review". Neuroscience & Biobehavioral Reviews. 118: 524–537. arXiv:2111.06126. doi:10.1016/j.neubiorev.2020.08.011. ISSN 0149-7634. PMID 32846163. S2CID 221257753.
49. Strohle, A.; Kumpfel, T.; Sonntag, A. (2000). "Paroxetine for Depersonalization Associated With Multiple Sclerosis". Am. J. Psychiatry. 157 (1): 150. doi:10.1176/ajp.157.1.150. PMID 10618046.
50. Wolf, Erika J.; Miller, Mark W.; Reardon, Annemarie F.; Ryabchenko, Karen A.; Castillo, Diane; Freund, Rachel (1 July 2012). "A Latent Class Analysis of Dissociation and Posttraumatic Stress Disorder: Evidence for a Dissociative Subtype". Archives of General Psychiatry. 69 (7): 698–705. doi:10.1001/archgenpsychiatry.2011.1574. ISSN 0003-990X. PMC 3390764. PMID 22752235.
51. Steinberg, Marlene (1994). Interviewer's guide to the structured clinical interview for DSM-IV dissociative disorders (SCID-D) (Rev ed.). Washington, DC: American Psychiatric Press. ISBN 978-1-58562-349-5. OCLC 320406013. from the original on 26 January 2024. Retrieved 2 November 2020.
52. Bernstein EM, Putnam FW (1986). "Development, reliability, and validity of a dissociation scale". J. Nerv. Ment. Dis. 174 (12): 727–35. doi:10.1097/00005053-198612000-00004. PMID 3783140. S2CID 20578794.
53. Mazzotti, Eva; Farina, Benedetto; Imperatori, Claudio; Mansutti, Federica; Prunetti, Elena; Speranza, Anna Maria; Barbaranelli, Claudio (2016). "Is the Dissociative Experiences Scale able to identify detachment and compartmentalization symptoms? Factor structure of the Dissociative Experiences Scale in a large sample of psychiatric and nonpsychiatric subjects". Neuropsychiatric Disease and Treatment. 12: 1295–1302. doi:10.2147/NDT.S105110. ISSN 1176-6328. PMC 4902245. PMID 27350746.
54. Saxe GN, van der Kolk BA, Berkowitz R, et al. (July 1993). "Dissociative disorders in psychiatric inpatients". Am J Psychiatry. 150 (7): 1037–42. doi:10.1176/ajp.150.7.1037. PMID 8317573.
55. Sugiura, Miyuki; Hirosawa, Masataka; Tanaka, Sumio; Nishi, Yasunobu; Yamada, Yasuyuki; Mizuno, Motoki (1 June 2009). "Reliability and validity of a Japanese version of the Cambridge depersonalization scale as a screening instrument for depersonalization disorder". Psychiatry and Clinical Neurosciences. 63 (3): 314–321. doi:10.1111/j.1440-1819.2009.01939.x. PMID 19566762. S2CID 6025282.
56. "ICD-11 - Mortality and Morbidity Statistics". icd.who.int. Archived from the original on 1 August 2018. Retrieved 27 October 2020.
57. Knefel, Matthias; Tran, Ulrich S.; Lueger-Schuster, Brigitte (October 2016). "The association of posttraumatic stress disorder, complex posttraumatic stress disorder, and borderline personality disorder from a network analytical perspective". Journal of Anxiety Disorders. 43: 70–78. doi:10.1016/j.janxdis.2016.09.002. ISSN 1873-7897. PMID 27637074. from the original on 6 November 2020. Retrieved 27 October 2020.
58. Şar, Vedat (28 December 2014). "The Many Faces of Dissociation: Opportunities for Innovative Research in Psychiatry". Clinical Psychopharmacology and Neuroscience. 12 (3): 171–179. doi:10.9758/cpn.2014.12.3.171. ISSN 1738-1088. PMC 4293161. PMID 25598819.
59. Lebois, Lauren A.M.; Harnett, Nathaniel G.; van Rooij, Sanne J.H.; Ely, Timothy D.; Jovanovic, Tanja; Bruce, Steven E.; House, Stacey L.; Ravichandran, Caitlin; Dumornay, Nathalie M.; Finegold, Katherine E.; Hill, Sarah B.; Merker, Julia B.; Phillips, Karlye A.; Beaudoin, Francesca L.; An, Xinming (September 2022). "Persistent Dissociation and Its Neural Correlates in Predicting Outcomes After Trauma Exposure". American Journal of Psychiatry. 179 (9): 661–672. doi:10.1176/appi.ajp.21090911. ISSN 0002-953X. PMC 9444876. PMID 35730162.
60. Kolk, Bessel A. van der (15 August 2017). "Developmental Trauma Disorder: Toward a rational diagnosis for children with complex trauma histories". Psychiatric Annals. 35 (5): 401–408. doi:10.3928/00485713-20050501-06. ISSN 0048-5713. from the original on 9 November 2020. Retrieved 11 December 2020.
61. Huppertz, Bernd (16 October 2018). Approaches to Psychic Trauma: Theory and Practice. Rowman & Littlefield. ISBN 978-1-4422-5815-0. from the original on 25 April 2021. Retrieved 24 December 2020.
62. Hunter, Elaine C. M.; Charlton, Jane; David, Anthony S. (2017). "Depersonalisation and derealisation: assessment and management". BMJ. 356: j745. doi:10.1136/bmj.j745. PMID 28336554. S2CID 206917634.
63. Medford N, Sierra M, Baker D, David AS (2005). "Understanding and treating depersonalization disorder". Advances in Psychiatric Treatment. 11 (5): 92–100. doi:10.1192/apt.11.2.92.
64. Wang, Sici; Zheng, Sisi; Zhang, Xiatian; Ma, Rui; Feng, Sitong; Song, Mingkang; Zhu, Hong; Jia, Hongxiao (11 July 2023). "The Treatment of Depersonalization-Derealization Disorder: A Systematic Review". Journal of Trauma & Dissociation. 25 (1). Informa UK Limited: 6–29. doi:10.1080/15299732.2023.2231920. ISSN 1529-9732. PMID 37431255. S2CID 259657390.
65. Spiegel, Herbert; Spiegel, David (2004). Trance and treatment : clinical uses of hypnosis (2nd ed.). Washington, DC: American Psychiatric Publishers. ISBN 1-58562-190-0. OCLC 54001039.
66. Bar, E., & Minnen van, A. (2011). Protocollaire behandeling van de depersonalisatiestoornis. In: G.P.J. Keijsers, A.van Minnen, & C.A.L. Hoogduin (red.). Protocollaire behandelingen voor volwassenen met psychische klachten. Arnhem, Boom Cure & Care publishers.
67. Sierra M (2008). "Depersonalization disorder: pharmacological approaches". Expert Rev Neurother. 8 (1): 19–26. doi:10.1586/14737175.8.1.19. PMID 18088198. S2CID 22180718.
68. Mauricio Sierra (13 August 2009). Depersonalization: A New Look at a Neglected Syndrome. Cambridge, UK: Cambridge University Press. p. 120. ISBN 978-0-521-87498-4. from the original on 2 September 2018. Retrieved 16 August 2019.
69. Mantovani, Antonio; Simeon, Daphne; Urban, Nina; Bulow, Peter; Allart, Anouk; Lisanby, Sarah (30 March 2011). "Temporo-parietal junction stimulation in the treatment of depersonalization disorder". Psychiatry Research. 186 (1): 138–140. doi:10.1016/j.psychres.2010.08.022. ISSN 0165-1781. PMID 20837362. S2CID 43658129.
70. Christopeit, Marie; Simeon, Daphne; Urban, Nina; Gowatsky, Jaimie; Lisanby, Sarah H.; Mantovani, Antonio (January 2014). "Effects of repetitive transcranial magnetic stimulation (rTMS) on specific symptom clusters in depersonalization disorder (DPD)". Brain Stimulation. 7 (1): 141–143. doi:10.1016/j.brs.2013.07.006. ISSN 1876-4754. PMID 23941986. S2CID 27003955.
71. Rachid, Fady (March 2017). "Treatment of a Patient With Depersonalization Disorder With Low Frequency Repetitive Transcranial Magnetic Stimulation of the Right Temporo-Parietal Junction in a Private Practice Setting". Journal of Psychiatric Practice. 23 (2): 145–147. doi:10.1097/PRA.0000000000000214. ISSN 1538-1145. PMID 28291041.
72. Michal, Matthias; Adler, Julia; Wiltink, Jörg; Reiner, Iris; Tschan, Regine; Wölfling, Klaus; Weimert, Sabine; Tuin, Inka; Subic-Wrana, Claudia; Beutel, Manfred E.; Zwerenz, Rüdiger (December 2016). "A case series of 223 patients with depersonalization-derealization syndrome". BMC Psychiatry. 16 (1): 203. doi:10.1186/s12888-016-0908-4. ISSN 1471-244X. PMC 4924239. PMID 27349226.
73. . Archived from the original on 28 January 2024.
74. Ross CA (1991). "Epidemiology of multiple personality disorder and dissociation". Psychiatric Clinics of North America. 14 (3): 503–17. doi:10.1016/S0193-953X(18)30286-7. PMID 1946021.
75. Lambert, M. V. (1 May 2002). "The Spectrum of Organic Depersonalization: A Review Plus Four New Cases". Journal of Neuropsychiatry. 14 (2): 141–154. doi:10.1176/appi.neuropsych.14.2.141. ISSN 0895-0172. from the original on 11 May 2024. Retrieved 11 May 2024.
76. Devillé, C.; Moeglin, C.; Sentissi, O. (2014). "Dissociative Disorders: Between Neurosis and Psychosis". Case Reports in Psychiatry. 2014: 1–6. doi:10.1155/2014/425892. ISSN 2090-682X. PMC 4227384. PMID 25405051.
77. Henri Frédéric Amiel's The Journal Intime 28 February 2007 at the Wayback Machine Retrieved June 2, 2007
78. Berrios GE, Sierra M (June 1997). "Depersonalization: a conceptual history". History of Psychiatry. 8 (30 Pt 2): 213–29. doi:10.1177/0957154X9700803002. PMID 11619439. S2CID 45671151.
79. Mayer-Gross W. (1935). "On depersonalization". British Journal of Medicine and Psychology (15): 103–126.
80. Simeon and Abugel p. 12 & 58
81. Varga, Somogy (2012). "Depersonalization and the Sense of Realness". Philosophy, Psychiatry, & Psychology. 19 (2): 103–113. ISSN 1086-3303. from the original on 11 May 2024. Retrieved 11 May 2024.
82. Sogomy, Varga (June 2012). "Depersonalization and the Sense of Realness". Philosophy, Psychiatry, & Psychology. 19 (2).
83. Simeon, D; Abugel J (2006). "The Blow of the Void: Depersonalization in Literature and Philosophy". Feeling unreal: depersonalization disorder and the loss of the self. United States: Oxford University Press. pp. 127–58. ISBN 978-0-19-517022-1.
84. Hirshberg, Glen (2003). The Snowman's Children: A Novel. New York, NY: Carroll & Graf. ISBN 978-0-7867-1253-3.
85. Suzanne Segal (1996). Collision With the Infinite: A Life Beyond the Personal Self. Blue Dove Press. ISBN 978-1-884997-27-3.
86. "A Lesson in Humility from Adam Duritz". Men's Health. 30 September 2014. from the original on 22 April 2016. Retrieved 30 May 2016.