In psychology, the term dissociation describes a wide array of experiences from mild detachment from immediate surroundings to more severe detachment from physical and emotional experience. The major characteristic of all dissociative phenomena involves a detachment from reality – rather than a loss of reality as in psychosis. Dissociative experiences are further characterized by the varied maladaptive mental constructions of an individual's natural imaginative capacity.
Dissociation is commonly displayed on a continuum. In mild cases, dissociation can be regarded as a coping mechanism or defense mechanisms in seeking to master, minimize or tolerate stress – including boredom or conflict. At the nonpathological end of the continuum, dissociation describes common events such as daydreaming while driving a vehicle. Further along the continuum are non-pathological altered states of consciousness.
More pathological dissociation involves dissociative disorders, including dissociative fugue and depersonalization disorder with or without alterations in personal identity or sense of self. These alterations can include: a sense that self or the world is unreal (depersonalization and derealization); a loss of memory (amnesia); forgetting identity or assuming a new self (fugue); and fragmentation of identity or self into separate streams of consciousness (dissociative identity disorder, formerly termed multiple personality disorder) and complex post-traumatic stress disorder.
Dissociative disorders are sometimes triggered by trauma, but may be preceded only by stress, psychoactive substances, or no identifiable trigger at all. The ICD-10 classifies conversion disorder as a dissociative disorder. The Diagnostic and Statistical Manual of Mental Disorders groups all dissociative disorders into a single category.
Although some dissociative disruptions involve amnesia, other dissociative events do not. Dissociative disorders are typically experienced as startling, autonomous intrusions into the person's usual ways of responding or functioning. Due to their unexpected and largely inexplicable nature, they tend to be quite unsettling.
The French philosopher and psychiatrist Pierre Janet (1859–1947) is considered to be the author of the concept of dissociation. Contrary to some conceptions of dissociation, Janet did not believe that dissociation was a psychological defense. Psychological defense mechanisms belong to Freud's theory of psychoanalysis, not to Janetian psychology. Janet claimed that dissociation occurred only in persons who had a constitutional weakness of mental functioning that led to hysteria when they were stressed. Although it is true that many of Janet's case histories described traumatic experiences, he never considered dissociation to be a defense against those experiences. Quite the opposite: Janet insisted that dissociation was a mental or cognitive deficit. Accordingly, he considered trauma to be one of many stressors that could worsen the already-impaired "mental efficiency" of a hysteric, thereby generating a cascade of hysterical (in today's language, "dissociative") symptoms.
Although there was great interest in dissociation during the last two decades of the nineteenth century (especially in France and England), this interest rapidly waned with the coming of the new century. Even Janet largely turned his attention to other matters. On the other hand, there was a sharp peak in interest in dissociation in America from 1890 to 1910, especially in Boston as reflected in the work of William James, Boris Sidis, Morton Prince, and William McDougall. Nevertheless, even in America, interest in dissociation rapidly succumbed to the surging academic interest in psychoanalysis and behaviorism. For most of the twentieth century, there was little interest in dissociation. Discussion of dissociation only resumed when Ernest Hilgard (1977) published his neodissociation theory in the 1970s and when several authors wrote about multiple personality in the 1980s.
Carl Jung described pathological manifestations of dissociation as special or extreme cases of the normal operation of the psyche. This structural dissociation, opposing tension, and hierarchy of basic attitudes and functions in normal individual consciousness is the basis of Jung's Psychological Types. He theorized that dissociation is a natural necessity for consciousness to operate in one faculty unhampered by the demands of its opposite.
Attention to dissociation as a clinical feature has been growing in recent years as knowledge of post-traumatic stress disorder increased, due to interest in dissociative identity disorder and the multiple personality controversy, and as neuroimaging research and population studies show its relevance.
Measurement and diagnosis of dissociative disorder
Dissociation in community samples is most commonly measured by the Dissociative Experiences Scale. The DSM-IV considers symptoms such as depersonalization, derealization and psychogenic amnesia to be core features of dissociative disorders. However, in the normal population dissociative experiences that are not clinically significant are highly prevalent, with 60% to 65% of the respondents indicating that they have had some dissociative experiences. The SCID-D is a structured interview used to assess and diagnose dissociation.
Relation to trauma and abuse
Dissociation has been described as one of a constellation of symptoms experienced by some victims of multiple forms of childhood trauma, including physical, psychological, and sexual abuse. This is supported by studies which suggest that dissociation is correlated with a history of trauma. Dissociation appears to have a high specificity and a low sensitivity to having a self-reported history of trauma, which means that dissociation is much more common among those who are traumatized, yet at the same time there are many persons who have suffered from trauma but who do not show dissociative symptoms.
Adult dissociation when combined with a history of child abuse and otherwise interpersonal violence-related posttraumatic stress disorder (PTSD) has been shown to contribute to disturbances in parenting behavior, such as exposure of young children to violent media. Such behavior may contribute to cycles of familial violence and trauma.
Symptoms of dissociation resulting from trauma may include depersonalization, psychological numbing, disengagement, or amnesia regarding the events of the abuse. It has been hypothesized that dissociation may provide a temporarily effective defense mechanism in cases of severe trauma; however, in the long term, dissociation is associated with decreased psychological functioning and adjustment. Other symptoms sometimes found along with dissociation in victims of traumatic abuse (often referred to as "sequelae to abuse") include anxiety, PTSD, low self-esteem, somatization, depression, chronic pain, interpersonal dysfunction, substance abuse, self-mutilation and suicidal ideation or actions. These symptoms may lead the victim to erroneously present the symptoms as the source of the problem.
Child abuse, especially chronic abuse starting at early ages, has been related to high levels of dissociative symptoms in a clinical sample, including amnesia for abuse memories. A non-clinical sample of adult women linked increased levels of dissociation to sexual abuse by a significantly older person prior to age 15, and dissociation has also been correlated with a history of childhood physical and sexual abuse. When sexual abuse is examined, the levels of dissociation were found to increase along with the severity of the abuse.
A 2012 review article supports the hypothesis that current or recent trauma may affect an individual's assessment of the more distant past, changing the experience of the past and resulting in dissociative states.
Psychoactive drugs can often induce a state of temporary dissociation. Substances with dissociative properties include ketamine, nitrous oxide, alcohol, LSD, tiletamine, marijuana, dextromethorphan, MK-801, PCP, methoxetamine, salvia, muscimol, atropine, diphenhydramine (in mid to high doses), and ibogaine.
- Altered state of consciousness
- Coping (psychology)
- Dissociative disorder
- Dissociative Experiences Scale
- Dissociative Identity Disorder
- Dissociative substance
- Emotional detachment
- Fantasy prone personality
- International Society for the Study of Trauma and Dissociation
- Psychological numbing
- Repressed memory
- Splitting (psychology)
- Dell P. F. (March 2006). "A new model of dissociative identity disorder". Psychiatric Clinics North America 29: 1–26, vii. doi:10.1016/j.psc.2005.10.013. PMID 16530584.
- Butler L.D. et al. (July 1996). "Hypnotizability and traumatic experience: a diathesis-stress model of dissociative symptomatology". American Journal of Psychiatry 153 (7 Suppl): 42–63. PMID 8659641.
- Gleaves D. H., May M. C., Cardeña, E. (June 2001). "An examination of the diagnostic validity of dissociative identity disorder". Clinical Psychology Review 21 (4): 577–608. doi:10.1016/S0272-7358(99)00073-2. PMID 11413868.
- Dell P. F. (2006). "The multidimensional inventory of dissociation (MID): A comprehensive measure of pathological dissociation". Journal of Trauma Dissociation 7 (2): 77–106. doi:10.1300/J229v07n02_06. PMID 16769667.
- Dell, P. F., & O'Neil, J. A. (2009). "Preface". In P.F. Dell & J.A. O'Neil. Dissociation and the dissociative disorders: DSM-V and beyond. New York: Routledge. pp. xix-xxi.
- Weiten, W. & Lloyd, M.A. (2008). Psychology Applied to Modern Life (9 ed.). Wadsworth Cengage Learning. ISBN 0-495-55339-5.
- Snyder, C.R., ed. (1999). Coping: The Psychology of What Works. New York: Oxford University Press. ISBN 0-19-511934-7.
- Zeidner, M. & Endler, N.S., ed. (1996). Handbook of Coping: Theory, Research, Applications. New York: John Wiley & Sons. ISBN 0-471-59946-8.
- Lynn S & Rhue JW (1994). Dissociation: clinical and theoretical perspectives. Guilford Press ISBN 978-0-89862-186-0. pp. [http://books.google.ca/books?id=BWLockQL714C&pg=PA19#v=onepage&q&f=false 19.
- Van der Kolk, B. A., Van der Hart, O., & Marmar, C. R. (1996). "Dissociation and information processing in posttraumatic stress disorder". In B. A. van der Kolk, A. C. McFarlane, & L. Weisaeth. Traumatic stress: The effects of overwhelming experience on mind, body, and society. New York: Guilford Press. pp. 303–327.
- Coons PM (June 1999). "Psychogenic or dissociative fugue: a clinical investigation of five cases". Psychological Reports 84 (3 Pt 1): 881–6. doi:10.2466/PR0.84.3.881-886. PMID 10408212.
- Kritchevsky M, Chang J, Squire LR (2004). "Functional Amnesia: Clinical Description and Neuropsychological Profile of 10 Cases". Learning and Memory 11: 213–26. doi:10.1101/lm.71404. PMC 379692. PMID 15054137.
- Abugel J & Simeon D (2006). Feeling unreal: depersonalization disorder and the loss of the self. Oxford: Oxford University Press. p. 17. ISBN 0-19-517022-9.
- American Psychiatric Association (June 2000). Diagnostic and Statistical Manual of Mental Disorders-IV (Text Revision). Arlington, VA, USA: American Psychiatric Publishing, Inc. pp. 519–534. doi:10.1176/appi.books.9780890423349. ISBN 978-0-89042-024-9.
- Van IJzendoorn MH, M; Schuengel C (1996). "The measurement of dissociation in normal and clinical populations: meta-analytic validation of the dissociative experiences scale (DES)". Clinical Psychology Review 16 (5): 365–382. doi:10.1016/0272-7358(96)00006-2.
- Ellenberger, H. F. (1970). The discovery of the unconscious: the history and evolution of dynamic psychiatry. New York: BasicBooks. ISBN 0-465-01673-1.
- Janet, P (1893/1901/1977). The mental state of hystericals: A study of mental stigmata and mental accidents. Washington, DC: University Publications of America. ISBN 0-89093-166-6.
- Janet, P (1920/1929/1965). The major symptoms of hysteria. New York: Hafner Publishing Company. ISBN 1-4325-0431-2.
- McDougall, W (1926). Outline of abnormal psychology. New York: Charles Scribner's Sons.
- Mitchell, TW (1921). The psychology of medicine. London: Methuen. ISBN 0-8274-4240-8.
- Mitchell, TW (1923/2007). Medical psychology and psychical research. New York: E. P. Dutton and Company. ISBN 1-4067-3500-0.
- Jung, C.G. (1991). Psychological types. Routledge London. ISBN 978-0-7100-6299-4.
- Scaer, Robert C. (2001). The Body Bears the Burden: Trauma, Dissociation, and Disease. Binghamton, NY: Haworth Medical Press. pp. 97–126. ISBN 0-7890-1246-4.
- Mario Di Fiorino, Maria Luisa Figueira: Dissociation. Dissociative Phenomena. Questions and Answers, Bridging Eastern & Western Psychiatry I,1, 1-134. 2003)
- Dissociative Disorders ( Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition )
- Waller, N.G.; Putnam, F.W.; Carlson, E.B. (1996). "Types of dissociation and dissociative types: A taxometric analysis of dissociative experiences". Psychological Methods 1: 300–321. doi:10.1037/1082-989X.1.3.300. Archived from the original on 2008-04-14. Retrieved 2008-01-31.
- Salter, Dr, Anna C.; Hilary Eldridge (1995). Transforming Trauma: A Guide to Understanding and Treating Adult Survivors. Sage Publications Inc. p. 220. ISBN 0-8039-5509-X.
- Myers, John E.B. (2002). The APSAC Handbook on Child Maltreatment, Second Edition. Sage Publications. p. 63. ISBN 0-7619-1992-9.
- van der Kolk, B.A. et al. (1996). "Dissociation, somatization, and affect dysregulation: the complexity of adaptation of trauma". American Journal of Psychiatry 153 (7 Suppl): 83–93. PMID 8659645. Retrieved 2008-05-13.
- Briere J (2006). "Dissociative symptoms and trauma exposure: specificity, affect dysregulation, and posttraumatic stress". Journal of Nervous and Mental Disorders 194: 78–82. doi:10.1097/01.nmd.0000198139.47371.54. PMID 16477184.
- Schechter DS, Gross A. et al.(2009). Is maternal PTSD associated with greater exposure of very young children to violent media? Journal of Trauma and Stress. 22(6), 658-62.
- Briere, John (1992). "Methodological Issues in the Study of Sexual Abuse Effects" (PDF). Journal of Consulting and Clinical Psychology 60 (2): 196–203. doi:10.1037/0022-006X.60.2.196. PMID 1592948.
- Merckelbach H., Muris P. (2001). "The causal link between self-reported trauma and dissociation: a critical review". Behaviour Research and Therapy 39 (3): 245–54. doi:10.1016/S0005-7967(99)00181-3. PMID 11227807. Retrieved 2008-05-13.
- Chu, J.; et al. (May 1999). "Memories of childhood abuse: dissociation, amnesia, and corroboration". American Journal of Psychiatry 156: 749–55. PMID 10327909.
- Briere, J., Runtz, M. (1988). "Symptomatology associated with childhood sexual victimization in a nonclinical adult sample". Child Abuse and Neglect 12: 51–59. doi:10.1016/0145-2134(88)90007-5. PMID 3365583.
- Briere, J., Runtz, M. (1990). "Augmenting Hopkins SCL scales to measure dissociative symptoms: data from two nonclinical samples". Journal of Personality Assessment 55 (1–2): 376–9. doi:10.1207/s15327752jpa5501&2_35. PMID 2231257.
- Draijer, N.; Langeland W (March 1999). "Childhood trauma and perceived parental dysfunction in the etiology of dissociative symptoms in psychiatric inpatients". American Journal of Psychiatry 156: 379–85. doi:10.1016/j.biopsych.2003.08.018. PMID 10080552.
- Stern DB (January 2012). "Witnessing across time: accessing the present from the past and the past from the present". The Psychoanalytic Quarterly 81 (1): 53–81. PMID 22423434.
- Giannini, AJ (1997). Drugs of Abuse (2nd ed.). Los Angeles: Practice Management Information Corp. ISBN 1-57066-053-0.
- International Society for the Study of Trauma and Dissociation
- The official journal of the International Society for the Study of Dissociation (ISSD), published between 1988 and 1997