Editing Depersonalization

{{Short description|Anomaly of self-awareness}}
{{For|social philosophy|objectification|dehumanization}}
'''Depersonalization''' is a [[Dissociation (psychology)|dissociative]] phenomenon characterized by a subjective feeling of detachment from oneself, manifesting as a sense of disconnection from one's thoughts, emotions, sensations, or actions, and often accompanied by a feeling of observing oneself from an external perspective.<ref>{{cite journal |pmid=11580008 |year=2001 |last1=Sierra |first1=M. |title=The phenomenological stability of depersonalization: Comparing the old with the new |journal=The Journal of Nervous and Mental Disease |volume=189 |issue=9 |pages=629–36 |last2=Berrios |first2=G. E. |doi=10.1097/00005053-200109000-00010 |s2cid=22920376}}</ref><ref name=":0">{{Cite journal |last1=Hunter |first1=E. C. M. |last2=Sierra |first2=M. |last3=David |first3=A. S. |date=2004-01-01 |title=The epidemiology of depersonalisation and derealisation |url=https://doi.org/10.1007/s00127-004-0701-4 |journal=Social Psychiatry and Psychiatric Epidemiology |language=en |volume=39 |issue=1 |pages=9–18 |doi=10.1007/s00127-004-0701-4 |pmid=15022041 |issn=1433-9285|url-access=subscription }}</ref> Subjects perceive that the world has become vague, dreamlike, surreal, or strange, leading to a diminished sense of individuality or identity. Those affected often feel as though they are observing the world from a distance,<ref>{{Cite news |title=Depersonalization-derealization disorder – Symptoms and causes |url=https://www.mayoclinic.org/diseases-conditions/depersonalization-derealization-disorder/symptoms-causes/syc-20352911 |access-date=2022-03-28 |website=[[Mayo Clinic]] |language=en |archive-date=2017-10-08 |archive-url=https://web.archive.org/web/20171008030114/https://www.mayoclinic.org/diseases-conditions/depersonalization-derealization-disorder/symptoms-causes/syc-20352911 |url-status=live }}</ref> as if separated by a barrier "behind glass".<ref name=":0" /> They maintain insight into the subjective nature of their experience, recognizing that it pertains to their own perception rather than altering objective reality. This distinction between subjective experience and objective reality distinguishes depersonalization from [[delusion]]s, where individuals firmly believe in false perceptions as genuine truths. Depersonalization is also distinct from [[derealization]], which involves a sense of detachment from the external world rather than from oneself.<!-- This statement is pretty much a 'derealization' symptom, in which the outside world becomes less real, compared with 'depesonalization' in which oneself becomes less real. Not verified in the body either: a good candidate for dropping. -->

[[Depersonalization-derealization disorder]] refers to chronic depersonalization, classified as a [[dissociative disorder]]<ref name="DSM-5">{{cite book |ref={{harvid|DSM-5|2013}} |author=[[American Psychiatry Association]] |title=Diagnostic and Statistical Manual of Mental Disorders | edition=5th |date=2013 |publisher=American Psychiatric Publishing |location=Arlington |isbn=978-0-89042-555-8 |chapter=Dissociative Disorders |pages=[https://archive.org/details/diagnosticstatis0005unse/page/291 291-307] |chapter-url=https://archive.org/details/diagnosticstatis0005unse/page/291}}</ref> in both the [[DSM-4]] and the [[DSM-5]], which underscores its association with disruptions in consciousness, memory, identity, or perception.<ref name=":1">{{Cite journal |last1=Salami |first1=Abbas |last2=Andreu-Perez |first2=Javier |last3=Gillmeister |first3=Helge |date=November 2020 |title=Symptoms of depersonalisation/derealisation disorder as measured by brain electrical activity: A systematic review |url=https://doi.org/10.1016/j.neubiorev.2020.08.011 |journal=Neuroscience & Biobehavioral Reviews |volume=118 |pages=524–537 |doi=10.1016/j.neubiorev.2020.08.011 |pmid=32846163 |issn=0149-7634 |arxiv=2111.06126 |access-date=2024-03-29 |archive-date=2024-04-12 |archive-url=https://web.archive.org/web/20240412133647/https://www.sciencedirect.com/science/article/abs/pii/S0149763420305492?via%3Dihub |url-status=live }}</ref> This classification is based on the findings that depersonalization and derealization are prevalent in other dissociative disorders including [[dissociative identity disorder]].<ref name="Sadock2017-DPD-Criteria-Change">{{harvp|Dissociative Disorders|2017|loc=CHANGES IN DIAGNOSTIC CRITERIA TO THE DISSOCIATIVE DISORDERS, Changes to the Diagnostic Criteria for Depersonalization Disorder}}</ref>

Though degrees of depersonalization can happen to anyone who is subject to temporary anxiety or stress, chronic depersonalization is more related to individuals who have experienced a severe [[Psychological trauma|trauma]] or prolonged stress/anxiety. Depersonalization-derealization is the single most important symptom in the spectrum of dissociative disorders,{{CN|date=April 2025}} including [[dissociative identity disorder]] and "[[dissociative disorder not otherwise specified]]" (DD-NOS). It is also a prominent symptom in some other non-dissociative disorders, such as [[anxiety disorder]]s, [[clinical depression]], [[bipolar disorder]], [[schizophrenia]],<ref name="pmid23454432">{{cite journal |doi=10.1016/j.concog.2013.01.009 |pmid=23454432 |title=Anomalous self-experience in depersonalization and schizophrenia: A comparative investigation |journal=[[Consciousness and Cognition]] |volume=22 |issue=2 |pages=430–441 |year=2013 |last1=Sass |first1=Louis |last2=Pienkos |first2=Elizabeth |last3=Nelson |first3=Barnaby |last4=Medford |first4=Nick |s2cid=13551169}}</ref> [[schizoid personality disorder]], [[hypothyroidism]] or endocrine disorders,<ref name="Sharma 2014 63–66">{{Cite journal |last1=Sharma |first1=Kirti |last2=Behera |first2=Joshil Kumar |last3=Sood |first3=Sushma |last4=Rajput |first4=Rajesh |last5=Satpal |last6=Praveen |first6=Prashant |date=2014|title=Study of cognitive functions in newly diagnosed cases of subclinical and clinical hypothyroidism |journal=Journal of Natural Science, Biology, and Medicine |volume=5 |issue=1 |pages=63–66 |doi=10.4103/0976-9668.127290 |issn=0976-9668 |pmc=3961955 |pmid=24678200 |doi-access=free }}</ref> [[schizotypal personality disorder]], [[borderline personality disorder]], [[obsessive–compulsive disorder]], [[migraine]]s, and [[sleep deprivation]]; it can also be a symptom of some types of neurological [[seizure]], and it has been suggested that there could be common aetiology between depersonalization symptoms and panic disorder, on the basis of their high co-occurrence rates.<ref name=":0" />

In [[social psychology]], and in particular [[self-categorization theory]], the term ''[[Self-categorization theory#Depersonalization|depersonalization]]'' has a different meaning and refers to "the stereotypical perception of the self as an example of some defining social category".<ref name="Turner & Oakes (1986).">{{cite journal |last1=Turner |first1=John |last2=Oakes |first2=Penny |title=The significance of the social identity concept for social psychology with reference to individualism, interactionism and social influence |journal=[[British Journal of Social Psychology]] |volume=25 |issue=3 |pages=237–52 |year=1986 |doi=10.1111/j.2044-8309.1986.tb00732.x |doi-access=free}}</ref>

== Description ==
Individuals who experience depersonalization feel divorced from their own personal self by sensing their body sensations, feelings, emotions, behaviors, etc. as not belonging to the same person or identity.<ref>{{cite web | last=Spiegel | first=David | title=Depersonalization/Derealization Disorder | website=MSD Manual Professional Edition | date=2023-05-03 | url=https://www.msdmanuals.com/professional/psychiatric-disorders/dissociative-disorders/depersonalization-derealization-disorder | access-date=2025-03-06}}</ref> Often a person who has experienced depersonalization claims that things seem unreal or hazy. Also, a recognition of a [[self]] breaks down (hence the name). Depersonalization can result in very high [[anxiety]] levels, which further increase these perceptions.<ref>{{cite web |last=Hall-Flavin |first=Daniel |url=http://www.mayoclinic.com/health/depersonalization/AN00595 |title=Depersonalization disorder: A feeling of being 'outside' your body |access-date=2007-09-08 |archive-date=2007-09-29 |archive-url=https://web.archive.org/web/20070929111122/http://www.mayoclinic.com/health/depersonalization/AN00595 |url-status=live }}</ref>

Depersonalization is a subjective experience of unreality in one's self, while [[derealization]] is unreality of the outside world. Although most authors currently regard depersonalization (personal/self) and derealization (reality/surroundings) as independent constructs, many do not want to separate derealization from depersonalization.<ref>{{cite journal |last1=Radovic |first1=F. |last2=Radovic |first2=S. |year=2002 |title=Feelings of Unreality: A Conceptual and Phenomenological Analysis of the Language of Depersonalization |journal=[[Philosophy, Psychiatry, & Psychology]] |volume=9 |issue=3 |pages=271–9 |doi=10.1353/ppp.2003.0048 |s2cid=145074433}}</ref>

== History ==
In 1904, [[Freud]] described his own experience of depersonalization experience at the Athens' Acropolis. He described the incident 32 years later, in 1936.  He interpreted his experience as an [[Defence mechanism|unconscious psychological defense]], in which he was repressing feelings of guilt for outliving his father, whose cause of death remained unknown.<ref>{{Cite web |last=Freedman |first=Jake |date=2024-05-30 |title=Depersonalisation and the Superego |url=https://www.jakekanefreedman.com/post/depersonalisation-superego |website=Jake Freedman |url-status=dead |archive-url=https://web.archive.org/web/20240724021722/https://www.jakekanefreedman.com/post/depersonalisation-superego
 |archive-date=24 July 2024 |access-date=7 January 2025}}</ref>

In his case study of the [[Sergei Pankejeff|Wolf Man]], Freud emphasized that depersonalization and derealization serve psychologically defensive functions. A young Russian man known as the "Wolf Man" experienced derealization, which is the sensation of being separated from his surroundings by a veil. This description of being separated from one's surroundings by a veil is reminiscent of [[derealization]]. This symptom was accompanied by fear of wolves. Freud's case description revolves around the man's dream of white wolves in a tree peering at him through an open window.<ref>{{Cite book |last=Simeon |first=Daphne |url=https://www.google.co.uk/books/edition/Feeling_Unreal/ONLyq-mVLuIC?hl=en&gbpv=0 |title=Feeling Unreal: Depersonalization Disorder and the Loss of the Self |last2=Abugel |first2=Jeffrey |date=2008-11-07 |publisher=Oxford University Press |isbn=978-0-19-976635-2 |language=en}}</ref><ref>{{Cite book |last=Francis |first=Matthew |url=https://www.google.co.uk/books/edition/Depersonalization_and_Creative_Writing/_i9xEAAAQBAJ?hl=en&gbpv=1&dq=wolf+man+freud+%22depersonalization%22&pg=PT196&printsec=frontcover |title=Depersonalization and Creative Writing: Unreal City |date=2022-07-18 |publisher=Taylor & Francis |isbn=978-1-000-60315-6 |language=en}}</ref>

== Epidemiology ==
Despite the distressing nature of symptoms, estimating the prevalence rates of depersonalization is challenging due to inconsistent definitions and variable timeframes.<ref name=":0" />

Depersonalization is a symptom of anxiety disorders, such as [[panic disorder]].<ref>{{cite journal |vauthors=Sierra-Siegert M, David AS |title=Depersonalization and individualism: the effect of culture on symptom profiles in panic disorder |journal=[[Journal of Nervous and Mental Disease]] |volume=195 |issue=12 |pages=989–95 |date=December 2007 |pmid=18091192 |doi=10.1097/NMD.0b013e31815c19f7 |s2cid=7182322}}</ref><ref name="Simeon-2004">{{cite journal |author=Simeon D |year=2004 |title=Depersonalisation Disorder: A Contemporary Overview |journal=CNS Drugs |volume=18 |issue=6 |pages=343–54 |pmid=15089102 |doi=10.2165/00023210-200418060-00002 |s2cid=18506672}}</ref> It can also accompany [[sleep deprivation]] (often occurring when experiencing [[jet lag]]), [[migraine]],
[[epilepsy]] (especially [[temporal lobe epilepsy]],<ref name="depers">{{cite journal |author=Michelle V. Lambert |author2=Mauricio Sierra |author3=Mary L. Phillips |author4=Anthony S. David |title=The Spectrum of Organic Depersonalization: A Review Plus Four New Cases |journal=[[The Journal of Neuropsychiatry and Clinical Neurosciences]] |date=May 2002 |volume=14 |pages=141–54 |pmid=11983788 |issue=2 |doi=10.1176/appi.neuropsych.14.2.141}}</ref>
[[Focal seizure|complex-partial seizure]], both as part of the [[Aura (symptom)|aura]] and during the [[seizure]]<ref name="Sadock2017-Epid-DP-DR">{{harvp | Dissociative Disorders |2017 | loc = GENERAL POPULATION STUDIES OF DISSOCIATIVE DISORDERS, Epidemiology of Depersonalization and Derealization Symptoms. }}</ref>),
[[obsessive-compulsive disorder]], severe stress or trauma, [[anxiety]], the use of recreational drugs<ref>{{Cite web |url=https://www.mayoclinic.org/diseases-conditions/depersonalization-derealization-disorder/symptoms-causes/syc-20352911 |title=Depersonalization-derealization disorder – Symptoms and causes |website=[[Mayo Clinic]] |language=en |access-date=2019-11-20 |archive-date=2017-10-08 |archive-url=https://web.archive.org/web/20171008030114/https://www.mayoclinic.org/diseases-conditions/depersonalization-derealization-disorder/symptoms-causes/syc-20352911 |url-status=live }}</ref>
{{Em dash}}especially [[Cannabis (drug)|cannabis]], [[hallucinogens]], [[ketamine]], and [[MDMA]], certain types of [[meditation]], deep [[hypnosis]], extended mirror or [[crystal gazing]], [[sensory deprivation]], and mild-to-moderate [[head injury]] with little or full [[loss of consciousness]] (less likely if unconscious for more than 30 minutes).
[[Interoceptive exposure]] is a non-pharmacological method that can be used to induce depersonalization.<ref>{{cite journal |author1=Lickel J |author2=Nelson E |author3=Lickel A H |author4=Brett Deacon |year=2008 |title=Interoceptive Exposure Exercises for Evoking Depersonalization and Derealization: A Pilot Study |journal=[[Journal of Cognitive Psychotherapy]] |volume=22 |issue=4 |pages=321–30 |doi=10.1891/0889-8391.22.4.321 |s2cid=12746427}}</ref><ref name="Sharma 2014 63–66" />

In the general population, transient depersonalization and derealization are common, having a [[lifetime prevalence]] between 26 and 74%.<ref name=":0" /> A random community-based survey of 1,000 adults in the US rural south found a 1-year depersonalization prevalence rate at 19%. Standardized diagnostic interviews have reported prevalence rates of 1.2% to 1.7% over one month in UK samples, and a rate of 2.4% in a single-point Canadian sample.<ref name=":0" /> In clinical populations, prevalence rates range from 1% to 16%, with varying rates in specific psychiatric disorders such as panic disorder and unipolar depression.<ref name=":0" /> Co-occurrence between depersonalization/derealization and panic disorder is common, suggesting a possible common etiology. Co-morbidity with other disorders does not influence symptom severity consistently.<ref name="Simeon-2004" />

Depersonalization is reported 2–4 times more in women than in men,<ref>{{cite book |ref={{harvid|Kaplan and Sadock's Synopsis of Psychiatry|2015}} |last1=Sadock |first1=BJ |last2=Sadock |first2=VA |year=2015 |title=Kaplan and Sadock's Synopsis of Psychiatry |edition=11th |chapter=12: Dissociative Disorders |publisher=[[Wolters Kluwer]] |isbn=978-1-60913-971-1 |at=DEPERSONALIZATION/DEREALIZATION DISORDER, Epidemiology, pp. 454-455}}</ref> but depersonalization/derealization disorder is diagnosed approximately equally across men and women, with symptoms typically emerging around the age of 16.<ref name="Simeon-2004" />

A similar and overlapping concept called [[ipseity disturbance]] (ipse is Latin for "self" or "itself"<ref>{{cite journal |first1=Louis A. |last1=Sass |first2=Josef |last2=Parnas |year=2003 |title=Schizophrenia, Consciousness, and the Self |journal=[[Schizophrenia Bulletin]] |volume=29 |issue=3 |pages=427–44 |doi=10.1093/oxfordjournals.schbul.a007017 |pmid=14609238 |doi-access=free}}</ref>) may be part of the core process of [[schizophrenia]] spectrum disorders. However, specific to the schizophrenia spectrum seems to be "a ''dis''location of first-person perspective such that self and other or self and world may seem to be non-distinguishable, or in which the individual self or field of consciousness takes on an inordinate significance in relation to the objective or intersubjective world" (emphasis in original).<ref name="pmid23454432"/>

For the purposes of evaluation and measurement, depersonalization can be conceived of as a construct and scales are now available to map its dimensions in {{Clarify |text=time and space. |date=May 2020 |reason=The reference mentions depersonalization experieces include time & space distorations, but this is only one dimension. Please elaborate on this point.}}<ref>{{cite journal |doi=10.1016/S0165-1781(00)00100-1 |pmid=10725532 |title=The Cambridge Depersonalisation Scale: A new instrument for the measurement of depersonalisation |journal=[[Psychiatry Research]] |volume=93 |issue=2 |pages=153–164 |year=2000 |last1=Sierra |first1=Mauricio |last2=Berrios |first2=German E. |s2cid=206024895}}</ref> A study of undergraduate students found that individuals high on the depersonalization/derealization subscale of the [[Dissociative Experiences Scale]] exhibited a more pronounced [[cortisol]] response in [[Stress (biology)|stress]]. Individuals high on the absorption subscale, which measures a subject's experiences of concentration to the exclusion of awareness of other events, showed weaker cortisol responses.<ref name="pmid17435477">{{cite journal |last=Giesbrecht |first=T. |author2=T. Smeets |author3=H. Merckelbac |author4=M. Jelicic |s2cid=9283387 |title=Depersonalization experiences in undergraduates are related to heightened stress cortisol responses |journal=[[Journal of Nervous and Mental Disease]] |volume=195 |issue=4 |pages=282–87 |year=2007 |pmid=17435477 |doi=10.1097/01.nmd.0000253822.60618.60}}</ref>

== Causes ==
Depersonalization can arise from a variety of factors, of both a psychological and physiological nature. Common immediate precipitants include instances of [[Stress (biology)|severe stress]], [[Major depressive episode|depressive episodes]], [[panic attack]]s, and the consumption of psychoactive substances such as [[marijuana]] and [[hallucinogen]]s. Additionally, there exists a correlation between frequent depersonalization and [[Childhood trauma|childhood interpersonal trauma]], particularly cases involving [[Psychological abuse|emotional maltreatment.]]<ref name="Simeon-2004" />

A [[case-control study]] conducted at a specialized depersonalization clinic included 164 individuals with chronic depersonalization symptoms, of which 40 linked their symptoms to illicit drug use. [[Phenomenology (philosophy)|Phenomenological]] similarity between drug-induced and non-drug groups was observed, and comparison with [[Matching (statistics)|matched controls]] further supported the lack of distinction. The severity of clinical depersonalization symptoms remains consistent regardless of whether they are triggered by illicit drugs or psychological factors.<ref>{{Cite journal |last1=Medford |first1=Nicholas |last2=Baker |first2=Dawn |last3=Hunter |first3=Elaine |last4=Sierra |first4=Mauricio |last5=Lawrence |first5=Emma |last6=Phillips |first6=Mary L. |last7=David |first7=Anthony S. |date=December 2003 |title=Chronic depersonalization following illicit drug use: a controlled analysis of 40 cases |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2003.00548.x |journal=Addiction |language=en |volume=98 |issue=12 |pages=1731–1736 |doi=10.1111/j.1360-0443.2003.00548.x |pmid=14651505 |issn=0965-2140 |access-date=2024-03-30 |archive-date=2023-04-30 |archive-url=https://web.archive.org/web/20230430211010/https://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2003.00548.x |url-status=live |url-access=subscription }}</ref>

=== Pharmacological ===
Depersonalization has been described by some as a desirable state, particularly by those that have experienced it under the influence of mood-altering [[recreational drugs]]. It is an effect of [[dissociatives]] and [[psychedelics]], as well as a possible side effect of [[caffeine]], [[alcohol (drug)|alcohol]], [[amphetamine]], [[Cannabis (drug)|cannabis]], and [[antidepressants]].<ref>{{cite journal |last1=Stein |first1=M. B. |last2=Uhde |first2=TW |title=Depersonalization Disorder: Effects of Caffeine and Response to Pharmacotherapy |journal=[[Biological Psychiatry]] |volume=26 |issue=3 |pages=315–20 |date=July 1989 |doi=10.1016/0006-3223(89)90044-9 |pmid=2742946 |s2cid=34396397 |url=https://zenodo.org/record/1253828 |access-date=2019-07-12 |archive-date=2024-01-26 |archive-url=https://web.archive.org/web/20240126213205/https://zenodo.org/records/1253828 |url-status=live }}</ref><ref>{{cite journal |last=Raimo |first=E. B. |author2=R. A. Roemer |author3=M. Moster |author4=Y. Shan |title=Alcohol-Induced Depersonalization |journal=[[Biological Psychiatry]] |date=June 1999 |doi=10.1016/S0006-3223(98)00257-1 |volume=45 |pages=1523–6 |pmid=10356638 |issue=11|s2cid=34049706}}</ref><ref name="pmid14746427">{{cite journal |last=Cohen |first=P. R. |title=Medication-associated depersonalization symptoms: report of transient depersonalization symptoms induced by minocycline |journal=[[Southern Medical Journal]] |volume=97 |issue=1 |pages=70–73 |year=2004 |pmid=14746427 |doi=10.1097/01.SMJ.0000083857.98870.98 |s2cid=27125601}}</ref><ref>{{cite web |url=http://www.medscape.com/viewarticle/468728_3 |title=Medication-Associated Depersonalization Symptoms |publisher=medscape.com |access-date=2009-03-30 |archive-date=2015-02-14 |archive-url=https://web.archive.org/web/20150214055436/http://www.medscape.com/viewarticle/468728_3 |url-status=live }}</ref><ref>{{cite journal |title=Depersonalization Again Finds Psychiatric Spotlight |journal=[[Psychiatric News]] |date=2003-08-15 |volume=38 |issue=16 |pages=18–30 |doi=10.1176/pn.38.16.0018 |last1=Arehart-Treichel |first1=Joan}}</ref> It is a classic [[Drug withdrawal|withdrawal]] symptom from many drugs.<ref name="pmid8104417">{{cite journal |last=Marriott |first=S. |author2=P. Tyrer |title=Benzodiazepine dependence: avoidance and withdrawal |journal=Drug Safety |volume=9 |issue=2 |pages=93–103 |year=1993 |pmid=8104417 |doi=10.2165/00002018-199309020-00003|s2cid=8550990 }}</ref><ref name="pmid15889607">{{cite journal |last=Shufman |first=E. |author2=A. Lerner |author3=E. Witztum |trans-title=Depersonalization after withdrawal from cannabis usage |language=he |journal=Harefuah |volume=144 |issue=4 |pages=249–51 and 303 |year=2005 |pmid=15889607|title=Depersonalization after withdrawal from cannabis usage}}</ref><ref name="pmid7085580">{{cite journal |last=Djenderedjian |first=A. |author2=R. Tashjian |title=Agoraphobia following amphetamine withdrawal |journal=The Journal of Clinical Psychiatry |volume=43 |issue=6 |pages=248–49 |year=1982 |pmid=7085580}}</ref><ref name="pmid9696914">{{cite journal |last=Mourad |first=I. |author2=M. Lejoyeux |author3=J. Adès |title=Evaluation prospective du sevrage des antidépresseurs |trans-title=Prospective evaluation of antidepressant discontinuation |language=fr |journal=[[L'Encéphale]] |volume=24 |issue=3 |pages=215–22 |year=1998 |pmid=9696914}}</ref>

[[Benzodiazepine dependence]], which can occur with long-term use of benzodiazepines, can induce chronic depersonalization symptomatology and perceptual disturbances in some people, even in those who are taking a stable daily dosage, and it can also become a protracted feature of the [[benzodiazepine withdrawal syndrome]].<ref>{{cite journal |doi=10.1016/0740-5472(91)90023-4 |pmid=1675688 |title=Protracted withdrawal syndromes from benzodiazepines |journal=Journal of Substance Abuse Treatment |volume=8 |issue=1–2 |pages=19–28 |year=1991 |last1=Ashton |first1=Heather }}</ref><ref>{{cite journal |author=Terao T |author2=Yoshimura R |author3=Terao M |author4=Abe K |title=Depersonalization following nitrazepam withdrawal |journal=[[Biological Psychiatry]] |volume=31 |issue=2 |pages=212–3 |date=1992-01-15 |pmid=1737083 |doi=10.1016/0006-3223(92)90209-I |s2cid=26522217}}</ref>

Lieutenant Colonel [[Dave Grossman (author)|Dave Grossman]], in his book ''[[On Killing]]'', suggests that military training artificially creates depersonalization in soldiers, suppressing [[empathy]] and making it easier for them to kill other human beings.<ref>{{Cite book |last=Grossman |first=Dave |title=On Killing: The Psychological Cost of Learning to Kill in War and Society |publisher=Back Bay Books |year=1996 |isbn=978-0-316-33000-8 |url=https://books.google.com/books?id=BewqAwAAQBAJ&q=depersonalization}}</ref>

[[Graham Reed (psychologist)|Graham Reed]] (1974) claimed that depersonalization occurs in relation to the experience of falling in love.<ref>{{cite book |last1=Reed |first1=Graham |year=1972 |title=The Psychology of Anomalous Experience |url=https://archive.org/details/amf00grah |url-access=registration |publisher=Hutchinson |page=[https://archive.org/details/amf00grah/page/127 127] |isbn=9780091132408}}</ref>

=== Situational ===
Experiences of depersonalization/derealization occur on a continuum, ranging from momentary episodes in healthy individuals under conditions of [[Stress (biology)|stress]], [[fatigue]], or [[Drug|drug use]], to severe and chronic disorders that can persist for decades.<ref name=":0" /> Several studies found that up to 66% of individuals in [[Near-death experience|life-threatening accidents]] report at least transient depersonalization during or immediately after the accidents.<ref name="Sadock2017-Epid-DP-DR" />

Several studies, but not all, found age to be a significant factor: [[adolescents]] and [[young adults]] in the normal population reported the highest rate. In a study, 46% of college students reported at least one significant episode in the previous year. In another study, 20% of patients with minor head injury experience significant depersonalization and derealization.

In [[general infantry]] and [[special forces]] soldiers, measures of depersonalization and derealization increased significantly after [[Military education and training|training]] that includes experiences of uncontrollable stress, semi-starvation, [[sleep deprivation]], as well as lack of control over [[hygiene]], movement, [[communications]], and [[social interaction]]s.<ref name="Sadock2017-Epid-DP-DR" />

=== Biological ===
Studies have linked dysregulation of the [[immune system]] with depersonalisation.<ref>{{Cite journal |last=Zheng |first=Sisi |last2=Feng |first2=Sitong |last3=Song |first3=Nan |last4=Chen |first4=Guangyao |last5=Jia |first5=Yuan |last6=Zhang |first6=Guofu |last7=Liu |first7=Min |last8=Li |first8=Xue |last9=Ning |first9=Yanzhe |last10=Wang |first10=Dan |last11=Jia |first11=Hongxiao |date=2024-05-27 |title=The role of the immune system in depersonalisation disorder |url=https://www.tandfonline.com/doi/full/10.1080/15622975.2024.2346096 |journal=The World Journal of Biological Psychiatry |language=en |volume=25 |issue=5 |pages=291–303 |doi=10.1080/15622975.2024.2346096 |issn=1562-2975|url-access=subscription }}</ref> Researchers compared protein expression in serum samples of individuals with [[Depersonalization-derealization disorder|depersonalisation/derealization disorder]] (DPDR, DDD) and healthy controls, and found that many key proteins involved in maintaining [[homeostasis]] were present at altered levels. Decreased levels of [[C-reactive protein|C-reactive protein (CRP)]], [[Complement component 1q|complement C1q subcomponent subunit B]], and apolipoprotein A-IV, and increased levels of alpha-1-antichymotrypsin (SERPINA3) were observed in patients with DPDR. Furthermore, expressions of CRP and SERPINA3 were found to be linked with the ability to inhibit cognitive interference of DPDR.

== Psychobiological mechanisms ==
{{See also|Symptoms of victimization}}

=== Proximate mechanism ===
Depersonalization involves disruptions in the integration of [[interoceptive]] and [[Proprioception|exteroceptive]] signals, particularly in response to acute anxiety or [[Traumatic memories|trauma-related events]]. Studies spanning from 1992 to 2020 have highlighted abnormalities in [[primary somatosensory cortex]] processing and [[Insular cortex|insula]] activity as contributing factors to depersonalization experiences.<ref name=":1" /> Additionally, abnormal [[EEG]] activities, notably in the theta band, suggest potential biomarkers for emotion processing, attention, and working memory, though specific oscillatory signatures associated with depersonalization are yet to be determined.<ref name=":1" /> Reduced brain activities in sensory processing units, along with alterations in visceral signal processing regions, are observed, particularly in the early stages of [[Information processing theory|information processing]].<ref name=":1" /><ref name="Simeon-2004" />

Furthermore, [[Vestibular system|vestibular]] signal processing, crucial for balance and spatial orientation, is increasingly recognized as a factor contributing to feelings of disembodiment during depersonalization experiences. Research suggests that abnormal activity in the [[left hemisphere]] may play a role, although abnormalities in right hemisphere brain activity, responsible for self-awareness and emotion processing, may also contribute to depersonalization symptoms. Higher activity in the [[Parietal lobe|right parietal lobe's]] [[angular gyrus]] has been linked to more severe depersonalisation, supporting this idea.<ref name=":1" />

Potential involvement of [[Serotonin|serotonergic]], [[Opioid|endogenous opioid]], and [[Glutamatergic neurotransmission|glutamatergic NMDA]] pathways has also been proposed, alongside alterations in metabolic activity in the [[Sensory nervous system|sensory association cortex]], [[Prefrontal cortex|prefrontal hyperactivation]], and [[Limbic system|limbic inhibition]] in response to [[aversive stimuli]] revealed by [[brain imaging]] studies.<ref name="Simeon-2004" />

In addition to this, research suggests that individuals with depersonalization often exhibit [[Autonomic nervous system|autonomic blunting]], characterized by reduced physiological responses to stressors or emotional stimuli. This blunting may reflect a diminished capacity to engage with the external world or to experience emotions fully, contributing to the subjective sense of detachment from oneself.<ref name=":0" /> Additionally, dysregulation of the [[HPA axis]], which governs the body's stress response system, is frequently observed in individuals who experience depersonalization. This dysregulation can manifest as alterations in [[Cortisol|cortisol levels]] and responsiveness to stress, potentially exacerbating feelings of detachment and unreality.<ref name=":1" />

=== Ultimate mechanism ===
Depersonalization is a classic response to acute [[Psychological trauma|trauma]], and may be highly prevalent in individuals involved in different traumatic situations including [[motor vehicle collision]] and [[imprisonment]].<ref name=Sadock2017-DPD-Criteria-Change />

Psychologically depersonalization can, just like dissociation in general, be considered a type of coping mechanism, used to decrease the intensity of unpleasant experience, whether that is something as mild as [[Psychological stress|stress]] or something as severe as chronically high [[anxiety]] and [[post-traumatic stress disorder]].<ref name=Domain-Dissociation-1994 />

The decrease in [[anxiety]] and psychobiological hyperarousal helps preserving adaptive behaviors and resources under threat or danger.<ref name=Sadock2017-DPD-Criteria-Change />

Depersonalization is an overgeneralized reaction in that it doesn't diminish just the unpleasant experience, but more or less all experience – leading to a feeling of being detached from the world and experiencing it in a more bland way. An important distinction must be made between depersonalization as a mild, short-term reaction to unpleasant experience and depersonalization as a chronic symptom stemming from a severe mental disorder such as [[PTSD]] or [[dissociative identity disorder]].<ref name="Domain-Dissociation-1994">{{cite book |last1=Cardeña |first1=Etzel |chapter=The Domain of Dissociation |year=1994 |editor1-first=Steven J. |editor1-last=Lynn |editor2-first=Judith W. |editor2-last=Rhue |title=Dissociation: Clinical and theoretical perspectives |pages=15–31 |location=New York |publisher=[[Guilford Press]] |isbn=978-0-89862-186-0}}</ref>

Chronic symptoms may represent persistence of depersonalization beyond the situations under threat.<ref name=Sadock2017-DPD-Criteria-Change />

== Treatment ==
Currently, no universally accepted treatment guidelines have been established for depersonalization. Pharmacotherapy remains a primary avenue of treatment, with medications such as [[clomipramine]], [[fluoxetine]], [[lamotrigine]], and [[opioid antagonist]]s being commonly prescribed. However, it is important to note that none of these medications have demonstrated a potent anti-dissociative effect in managing symptoms.<ref name="Simeon-2004" />

In addition to pharmacological interventions, various psychotherapeutic techniques have been employed in attempts to alleviate depersonalization symptoms. Modalities such as [[Therapy|trauma-focused therapy]] and [[Cognitive behavioral therapy|cognitive-behavioral techniques]] have been utilized, although their efficacy remains uncertain and not firmly established.<ref name="Simeon-2004" />[[File:Depersonalization Disorder by Boris D. Ogñenovich.png|thumb|An attempt at a visual representation of depersonalization]]
Treatment is dependent on the underlying cause, whether it is organic or psychological in origin. If depersonalization is a symptom of neurological disease, then diagnosis and treatment of the specific disease is the first approach. Depersonalization can be a cognitive symptom of such diseases as [[amyotrophic lateral sclerosis]], [[Alzheimer's disease]], [[multiple sclerosis]] (MS), or any other neurological disease affecting the brain.<ref>{{cite web |title=Overview of Child Neglect and Abuse – Overview of Child Neglect and Abuse |url=https://www.msdmanuals.com/home/children-s-health-issues/child-neglect-and-abuse/overview-of-child-neglect-and-abuse |website=MSD Manual Consumer Version |access-date=28 June 2024 |language=en}}</ref><ref>{{cite journal |last1=Murphy |first1=RJ |title=Depersonalization/Derealization Disorder and Neural Correlates of Trauma-related Pathology: A Critical Review. |journal=Innovations in Clinical Neuroscience |date=January 2023 |volume=20 |issue=1–3 |pages=53–59 |pmid=37122581 |pmc=10132272}}</ref> For those with both depersonalization and [[migraine]], [[tricyclic antidepressant]]s are often prescribed.

If depersonalization is a symptom of psychological causes such as developmental trauma, treatment depends on the diagnosis. In case of [[dissociative identity disorder]] or DD-NOS as a developmental disorder, in which extreme developmental [[Psychological trauma|trauma]] interferes with formation of a single cohesive identity, treatment requires proper psychotherapy, and—in the case of additional (co-morbid) disorders such as [[eating disorders]]—a team of specialists treating such an individual. It can also be a symptom of [[borderline personality disorder]], which can be treated in the long term with proper psychotherapy and psychopharmacology.<ref name="pmid16960469">{{cite journal |doi=10.1097/01.WNF.0000228368.17970.DA |pmid=16960469 |title=Lamotrigine as an Add-on Treatment for Depersonalization Disorder |journal=[[Clinical Neuropharmacology]] |volume=29 |issue=5 |pages=253–258 |year=2006 |last1=Sierra |first1=Mauricio |last2=Baker |first2=Dawn |last3=Medford |first3=Nicholas |last4=Lawrence |first4=Emma |last5=Patel |first5=Maxine |last6=Phillips |first6=Mary L. |last7=David |first7=Anthony S. |s2cid=38595510}}</ref>

The treatment of chronic depersonalization is considered in [[depersonalization disorder]].

A 2001 Russian study showed that [[naloxone]], a drug used to reverse the intoxicating effects of opioid drugs, can successfully treat depersonalization disorder. According to the study: "In three of 14 patients, depersonalization symptoms disappeared entirely and seven patients showed a marked improvement. The therapeutic effect of naloxone provides evidence for the role of the endogenous opioid system in the pathogenesis of depersonalization."<ref name="pmid11448093">{{cite journal |doi=10.1177/026988110101500205 |pmid=11448093 |title=Effect of naloxone therapy on depersonalization: A pilot study |journal=[[Journal of Psychopharmacology]] |volume=15 |issue=2 |pages=93–95 |year=2001 |last1=Nuller |first1=Yuri L. |last2=Morozova |first2=Marina G. |last3=Kushnir |first3=Olga N. |last4=Hamper |first4=Nikita |s2cid=22934937 }}</ref> The anticonvulsant drug [[lamotrigine]] has shown some success in treating symptoms of depersonalization, often in combination with a [[selective serotonin reuptake inhibitor]] and is the first drug of choice at the depersonalisation research unit at King's College London.<ref name="pmid16960469"/><ref>{{cite journal |doi=10.1186/2050-7283-1-20 |pmid=25566370 |pmc=4269982 |title=Evidence-based treatment for Depersonalisation-derealisation Disorder (DPRD) |journal=BMC Psychology |volume=1 |issue=1 |pages=20 |year=2013 |last1=Somer |first1=Eli |last2=Amos-Williams |first2=Taryn |last3=Stein |first3=Dan J. |doi-access=free }}</ref><ref>{{cite journal |doi=10.1192/apt.11.2.92 |title=Understanding and treating depersonalisation disorder |journal=[[Advances in Psychiatric Treatment]] |volume=11 |issue=2 |pages=92–100 |year=2005 |last1=Medford |first1=Nick |last2=Sierra |first2=Mauricio |last3=Baker |first3=Dawn |last4=David |first4=Anthony S. |doi-access=free}}</ref>

== Research directions ==
Interest in DPDR has increased over the past few decades, leading to a large accumulation of literature on dissociative disorders. There has been a shift towards the use of research studies, rather than [[case studies]] to understand depersonalization.<ref name=":0" /> However, there remains a lack of solid consensus on its definition and scales used for assessment.<ref name=":0" /><ref name="Simeon-2004" /> Salami and colleagues argued that studies of [[electrophysiological]] depersonalization-derealization markers are urgently needed, and that future research should use analysis methods that can account for the integration of [[interoceptive]] and [[Proprioception|exteroceptive]] signals.<ref name=":1" />

The Depersonalisation Research Unit at the Institute of Psychiatry in London conducts research into [[depersonalization disorder]].<ref>{{Cite web |url=http://www.iop.kcl.ac.uk/iopweb/departments/home/?locator=911&context=main |title=Depersonalisation Research Unit – Institute of Psychiatry, London |access-date=2006-11-07 |archive-date=2007-01-18 |archive-url=https://web.archive.org/web/20070118095449/http://www.iop.kcl.ac.uk/iopweb/departments/home/?locator=911&context=main |url-status=live }}</ref> Researchers there use the acronym DPAFU (Depersonalisation and Feelings of Unreality) as a shortened label for the disorder.

In a 2020 article in the [[Journal Nature]], Vesuna, et al. describe experimental findings which show that layer 5 of the retrosplenial cortex is likely responsible for dissociative states of consciousness in mammals.

== See also ==
{{Columns-list|colwidth=22em|
* [[Social alienation|Alienation]]
* [[Brain fog]]
* [[Catatonic state]]
* [[Cognition]]
* [[Derealization]]
* [[Ego death]]
* [[Falling (sensation)]]
* [[Hallucinogen persisting perception disorder]]
* [[Human spirit]]
* [[Nina Searl]]
* [[Out-of-body experience]]
* [[Post-assault treatment of sexual assault victims]]
* [[Psychedelic experience]]
* [[Śūnyatā]]
* [[Spiritual crisis]]
* [[Weltschmerz]]
}}

== References ==
{{Reflist|30em}}

=== References ===
* {{cite book | ref = {{harvid | Dissociative Disorders |2017 }}  | last1 = Loewenstein | first1 = Richard J | last2 = Frewen | first2 = Paul | last3 = Lewis-Fernández | first3 = Roberto | editor1-last = Sadock | editor1-first = Virginia A | editor2-last = Sadock | editor2-first = Benjamin J | editor3-last = Ruiz | editor3-first = Pedro | year = 2017 | title = Kaplan & Sadock's Comprehensive Textbook of Psychiatry | edition = 10th | isbn = 978-1-4511-0047-1 | publisher = Wolters Kluwer | chapter = 20 Dissociative Disorders }}

{{Authority control}}

[[Category:Dissociative disorders]]
[[Category:Symptoms and signs of mental disorders]]
[[Category:Symptoms or signs involving perceptual disturbance]]