dissociative identity disorder dissociative identity disorder dissociative identity disorder (did), formerly known as multiple personality disorder, and commonly referred to as split personality disorder or dissociative personality disorder, is a member of the family of dissociative disorders classified by the dsm-5, dsm-5-tr, icd-10, icd-11, and merck manual for diagnosis. it remains a controversial diagnosis. dissociative identity disorderother namesmultiple personality disordersplit personality disorderdissociative personality disorderspecialtypsychiatry, clinical psychologysymptomsat least two distinct and relatively enduring personality states, recurrent episodes of dissociative amnesia, inexplicable intrusions into consciousness (e.g., voices, intrusive thoughts, impulses, trauma-related beliefs), alterations in sense of self, depersonalization and derealization, intermittent functional neurological symptoms, emotion and behavior dysregulation, schneiderian first-rank symptomscomplicationstrauma and shame-based beliefs, dissociative fugue, eating disorders, fibromyalgia, depression, anxiety, sleep disturbances (eg. sleep terrors, nightmares, sleepwalking, insomnia, hypersomnia), suicidality, self-harmdurationlong-termcauseschildhood traumarisk factorssuicide, interpersonal problems, aggressive behaviorsdifferential diagnosisother specified dissociative disorder, major depressive disorder, bipolar disorder, post-traumatic stress disorder, psychotic disorder, substance use disorder, schizotypal personality disorder, temporal lobe epilepsy,traumatic brain injury, seizure disorder, personality disordertreatmentpatient education, peer support, safety planning, grounding techniques, supportive care, psychotherapyfrequency~1.5–2% of psychiatric patients dissociative identity disorder is characterized by the presence of at least two distinct and relatively enduring personality states.(p331) the disorder is accompanied by memory gaps more severe than could be explained by ordinary forgetfulness.(p331) the personality states alternately show in a person's behavior;(p331) however, presentations of the disorder vary. other conditions that often occur in people with did include post-traumatic stress disorder, personality disorders (especially borderline, schizotypal and avoidant), depression, substance use disorders, conversion disorder, somatic symptom disorder, eating disorders, obsessive–compulsive disorder, and sleep disorders.(pp333–338) self-harm, non-epileptic seizures, flashbacks with amnesia for content of flashbacks, anxiety disorders, and suicidality are also common. did requires an unintegrated mind to form. genetic and biological factors are also believed to play a role. the diagnosis should not be made if the person's condition is better accounted for by substance use disorder, seizures, other medical problems, imaginative play in children, or religious practices.(p331) according to the dsm-5-tr, early life trauma, typically before the age of 10, can place someone at risk of developing dissociative identity disorder.(p334)across diverse geographic regions, 90% of individuals diagnosed with dissociative identity disorder report experiencing multiple forms of childhood abuse, such as neglect or severe bullying.(p334) other traumatic childhood experiences that have been reported include painful medical or surgical procedures,(p334) war,(p334) terrorism,(p334) attachment disturbance,(p334) natural disaster, cult, and occult abuse, loss of a loved one or loved ones, human trafficking,(p334) and dysfunctional family dynamics.(p334) there is no medication to treat did directly. medications can be used for comorbid disorders or targeted symptom relief, for example antidepressants or treatments to improve sleep, however. treatment generally involves supportive care and psychotherapy. the condition usually persists without treatment. it is believed to affect about 1.5% of the general population (based on a small us community sample) and 3% of those admitted to hospitals with mental health issues in europe and north america.(p334) did is diagnosed about six times more often in women than in men. the number of recorded cases increased significantly in the latter half of the 20th century, along with the number of identities reported by those affected. it is unclear whether increased rates of the disorder are due to better recognition or sociocultural factors such as mass media portrayals. the typical presenting symptoms in different regions of the world may also vary depending on culture, such as alter identities taking the form of possessing spirits, deities, ghosts, or mythical creatures and figures in cultures where normative possession states are common.(p335) the possession form of dissociative identity disorder is involuntary and distressing, and occurs in a way that violates cultural or religious norms.(p335) definitions dissociation, the term that underlies dissociative disorders including did, lacks a precise, empirical, and generally agreed upon definition.(p9) a large number of diverse experiences have been termed dissociative, ranging from normal failures in attention to the breakdowns in memory processes characterized by the dissociative disorders.(pp19–21) it is therefore unknown if there is a commonality between all dissociative experiences, or if the range of mild to severe symptoms is a result of different etiologies and biological structures. other terms used in the literature, including personality, personality state, identity, ego state, and amnesia, also have no agreed upon definitions. multiple competing models exist that incorporate some non-dissociative symptoms while excluding dissociative ones. due to the lack of consensus regarding terminology in the study of did, several terms have been proposed. one is ego state (behaviors and experiences possessing permeable boundaries with other such states but united by a common sense of self), while the other term is alters (each of which may have a separate autobiographical memory, independent initiative and a sense of ownership over individual behavior). ellert nijenhuis and colleagues suggest a distinction between personalities responsible for day-to-day functioning (associated with blunted physiological responses and reduced emotional reactivity, referred to as the "apparently normal part of the personality" or anp) and those emerging in survival situations (involving fight-or-flight responses, vivid traumatic memories and strong, painful emotions – the "emotional part of the personality" or ep). "structural dissociation of the personality" is used by onno van der hart and colleagues to distinguish dissociation they attribute to traumatic or pathological causes, which in turn is divided into primary, secondary and tertiary dissociation. according to this theory, primary dissociation prototypically involves one anp and one ep, while secondary dissociation prototypically involves an anp and at least two eps, and tertiary dissociation, typically characterized in did, is described as having at least two anps and at least two eps. others have suggested dissociation can be separated into two distinct forms, detachment and compartmentalization, the latter of which, involving a failure to control normally controllable processes or actions, is most evident in did. efforts to psychometrically distinguish between normal and pathological dissociation have been made. signs and symptoms the full presentation of dissociative identity disorder can onset at any age, although symptoms typically begin at ages 5–10. according to the fifth edition of the diagnostic and statistical manual of mental disorders (dsm-5), symptoms of did include "the presence of two or more distinct personality states" accompanied by the inability to recall personal information beyond what is expected through normal memory issues. other dsm-5 symptoms include a loss of identity as related to individual distinct personality states, loss of one's subjective experience of the passage of time, and degradation of a sense of self and consciousness. in each individual, the clinical presentation varies and the level of functioning can change from severe impairment to minimal impairment. the symptoms of dissociative amnesia are subsumed under a did diagnosis, and thus should not be diagnosed separately if did criteria are met. individuals with did may experience distress from both the symptoms of did (intrusive thoughts or emotions) and the consequences of the accompanying symptoms (dissociation rendering them unable to remember specific information). the majority of patients with did report childhood sexual or physical abuse. amnesia between identities may be asymmetrical; identities may or may not be aware of what is known by another. individuals with did may be reluctant to discuss symptoms due to associations with abuse, shame, and fear. did patients may also frequently and intensely experience time disturbances. around half of people with did have fewer than 10 identities and most have fewer than 100; although as many as 4,500 have been reported.(p 503) the average number of identities has increased over the past few decades, from two or three to now an average of approximately 16. however, it is unclear whether this is due to an actual increase in identities, or simply that the psychiatric community has become more accepting of a high number of compartmentalized memory components. comorbid disorders the psychiatric history frequently contains multiple previous diagnoses of various disorders and treatment failures. the most common presenting complaint of did is depression, with headaches being a common neurological symptom. comorbid disorders can include substance use disorder, eating disorders, anxiety disorders, bipolar disorder, and personality disorders. a significant percentage of those diagnosed with did have histories of borderline personality disorder and post-traumatic stress disorder (ptsd). presentations of dissociation in people with schizophrenia differ from those with did as not being rooted in trauma, and this distinction can be effectively tested, although both conditions share a high rate of dissociative auditory hallucinations. other disorders that have been found to be comorbid with did are somatization disorders, major depressive disorder, as well as history of a past suicide attempt, in comparison to those without a did diagnosis. disturbed and altered sleep has also been suggested as having a role in dissociative disorders in general and specifically in did, alterations in environments also largely affecting the did patient. individuals diagnosed with did demonstrate the highest hypnotizability of any clinical population. although did has high comorbidity and its development is related to trauma, there exists evidence to suggest that did merits a separate diagnosis from other conditions like ptsd. causes general there are two competing theories on what causes dissociative identity disorder to develop. the trauma-related model suggests that trauma or severe adversity in childhood, also known as developmental trauma, increases the risk of someone developing dissociative identity disorder. the non-trauma related model, also referred to as the sociocognitive model or the fantasy model, suggests that dissociative identity disorder is developed through high fantasy-proneness or suggestibility, roleplaying, or sociocultural influences. the dsm-5-tr states that "early life trauma (e.g., neglect and physical, sexual, and emotional abuse, usually before ages 5-6 years) represents a risk factor for dissociative identity disorder."(p333) other risk factors reported include painful medical procedures, war, terrorism, or being trafficked in childhood.(p333) dissociative disorders frequently occur after trauma, and the dsm-5-tr places them after the trauma- and stressor-related disorders to reflect this close relationship.(p329) trauma-related model main article: trauma model of mental disorders dissociative identity disorder is often conceptualized as "the most severe form of a childhood onset post-traumatic stress disorder." according to many researchers, the etiology of dissociative identity is multifactorial, involving a complex interaction between developmental trauma, sociocultural influences, and biological factors. people diagnosed with dissociative identity disorder often report that they have experienced physical or sexual abuse during childhood (although the accuracy of these reports has been disputed); others report overwhelming stress, serious medical illness or other traumatic events during childhood. they also report more historical psychological trauma than those diagnosed with any other mental illness. severe sexual, physical, or psychological trauma in childhood has been proposed as an explanation for its development; awareness, memories and emotions of harmful actions or events caused by the trauma are removed from consciousness, and alternate personalities or subpersonalities form with differing memories, emotions and behavior. dissociative identity disorder is attributed to extremes of stress or disorders of attachment. what may be expressed as post-traumatic stress disorder (ptsd) in adults may become dissociative identity disorder when occurring in children, possibly due to their greater use of imagination as a form of coping. possibly due to developmental changes and a more coherent sense of self past the age of six, the experience of extreme trauma may result in different, though also complex, dissociative symptoms and identity disturbances. a specific relationship between childhood abuse, disorganized attachment, and lack of social support are thought to be a necessary component of dissociative identity disorder. although what role a child's biological capacity to dissociate to an extreme level remains unclear, some evidence indicates a neurobiological impact of developmental stress. delinking early trauma from the etiology of dissociation has been explicitly rejected by those supporting the early trauma model. however, 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. giesbrecht et al. have suggested there is no actual empirical evidence linking early trauma to dissociation, and instead suggest that problems with neuropsychological functioning, such as increased distractibility in response to certain emotions and contexts, account for dissociative features. a middle position hypothesizes that trauma, in some situations, alters neuronal mechanisms related to memory. evidence is increasing that dissociative disorders are related both to a trauma history and to "specific neural mechanisms". it has also been suggested that there may be a genuine but more modest link between trauma and