by- D r S adaf S iddiqui moderator- D r P iyush P S ingh Dissociative disorders
Introduction History Classification Epidemiology Etiological theories Neurobiology Clinical features Dissociation in other psychiatric disorder Management
Introduction
Dissociation is a common defense/reaction to stressful or traumatic situations. Severe isolated traumas or repeated traumas may result in a person developing a dissociative disorder . A dissociative disorder impairs the normal state of awareness and limits or alters one’s sense of identity, memory or consciousness. Once considered rare, recent research indicates that dissociative symptoms are as common as anxiety and depression.
The concept of dissociative or conversion disorder has been described since antiquity. These disorders have been previously classified as ‘hysteria’, based on Egyptian theory of wandering uterus. The term dissociation has its origin in the constituent parts of the term: dis-association, which means disconnecting or lowering the strength of associated connections .
The common theme shared by dissociative disorders is a partial or complete loss of normal integration between memories of the past, awareness of identity and immediate sensations and control of body movements. This group of illness also lacks the evidence of proximate organic illness or pathophysiological disturbance, and the symptoms correspond to the ideas of the patient about how parts of body or mind malfunction or fail to function. Isaac & Chand, 2006; Bob, 2003
Evolution of concept
The ancient “wandering womb” hypothesis and also humoral theory remained prominent until the middle of the eighteenth century. “ Master organ theories” emerged in the 1700s and referred to the idea that master organs such as uterus, digestive system or nerves influenced the brain and resulted in nervous symptoms .
During the 1800s, the spinal irritation doctrine was expanded into reflex theory, which asserted that every organ in the body could reflexively influence every other organ. Charcot conceptualized hysteria as an inherited disease of the nervous system, caused by lesions of the nervous centers.
These lesions were called “functional” because they were presumed to exist but couldn’t be localized by the techniques of that time. Two of Charcot’s most important successors, Babinski and Janet, took divergent views.
Babinski describes that hysteria was caused by suggestion and could be removed by persuasion or counter suggestion. Pierre Janet established the concept of “dissociation” to describe the disruption of normal mental synthesis between ideas, acts and sensory and motor functions as seen in patients with hysterical symptoms (Gordon, 1984).
In his theory of dissociation, Janet referred to mental/ behavioural /affective states as “ psychological automatisms”. The psychological automatism was an elementary system of the mind, a complex act tuned to external and internal conditions, preceeded by an idea, and accompanied by an emotion.
Janet argued that psychological automatisms could be split off from consciousness under conditions of terror or severe stress, illness or fatigue, and function outside awareness of voluntary control (Van der Kolk , 1989 ). Neo-dissociation theory of Hilgard -1977, theory assumes that the mind is organized as a system of mental structures, which monitor and control experience, thought, and action in different domains.
In principle, each of the structures can process inputs and outputs independently of the others, although under ordinary circumstances each structure is in communication with the others, and several different structures might compete for a single input or output channel. Freud’s psychoanalytic understanding dominated twentieth-century understanding of conversion symptoms.
During the later part of 1890s, Freud followed Janet’s dissociation trauma hypothesis and, in his observation of eighteen hysterical patients, proposed childhood sexual trauma as the origin of their symptoms. Later , he coined the term “ conversion ” to describe the process by which unacceptable mental contents were transformed into somatic symptoms.
Whereas both the classical dissociation theory of Janet (1889) and the N eo-dissociation theory of Hilgard ( 1977) assume that the normal unity of consciousness is disrupted by an amnesia-like process, Woody and Bowers (1994) have offered an alternative view that many mental and behavioral functions are performed unconsciously and automatically to begin with, by specialized cognitive modules. Thus , some degree of dissociation is the natural state.
Classification: ICD 10 & DSM-5
Classification of Dissociative disorders is somewhat different in the two major classificatory systems. DSM-5 dissociative amnesia , dissociative identity disorder, depersonalization disorder, other specified dissociative disorder and unspecified dissociative disorder.
But in ICD 10, dissociative disorders include dissociative amnesia dissociative fugue, dissociative stupor, trance and possession disorder, dissociative disorders of movement and sensation. mixed dissociative disorders (i.e., Ganser’s syndrome , multiple personality disorder, transient dissociative disorder occurring in childhood and adolescence and other specified dissociative disorders).
Changes in dsm-5 Major changes in dissociative disorders in DSM-5 include the following: 1 ) de-realization is included in the name and symptom structure of what previously was called depersonalization disorder and is now called depersonalization/de-realization disorder . 2 ) dissociative fugue is now a specifier of dissociative amnesia rather than a separate diagnosis.
3) the criteria for dissociative identity disorder have been changed to indicate that symptoms of disruption of identity may be reported as well as observed, and that gaps in the recall of events may occur for everyday and not just traumatic events.
In sum, both classification systems agree that dissociation relates to the (autobiographical) memory system, consciousness and the domain of personal identity. However , the ICD-10 acknowledges that it also may involve the sensory and motor systems, leading to symptoms which are subsumed under the term of conversion .
In contrast, the DSM-5 restricts dissociation to the level of psychic functions and systems. Consequently, conversion disorders are one among the somatoform disorders in the DSM-5, while the ICD-10 claims that dissociative and conversion disorders represent one category that is independent from the somatoform disorders.
epidemiology
The first systematic general population study of the prevalence of dissociative disorder was done by Ross et al (1990). They found dissociative amnesia in 6%, dissociative identity disorder in 1.3%, depersonalization disorder in 2.8% and dissociative disorder NOS in 0.2% in a random sample of 1055 adults from Canada. Reported rates of dissociative disorder of movement and sensation (conversion disorder) have varied widely, ranging from 11/100,000 to 500/100,000 in general population samples.
Dissociative amnesia,has been reported in approximately 1.8 to 6 percent of general population samples, with 7.3 percent of a general population sample of Turkish women meeting diagnostic criteria for dissociative amnesia . A survey of a random sample of 1,000 adults in the rural South found a 1-year prevalence of 19 percent for depersonalization and 14 percent for de-realization .
Studies of general medical/surgical inpatients have identified conversion symptom rates ranging between 1% and 14% (APA, 2000) Samples of psychiatric inpatients, outpatients, and substance abuse patients in North America, Europe, and Asia have found that between 5 and 30 percent of patients could be diagnosed with a dissociative disorder when screened.
Overall, the prevalence of dissociative disorders in inpatient and outpatient psychiatric settings seems to be around 10%, while approximately half of them (5%) has DID, the most severe type of dissociative disorders. (Epidemiology of Dissociative Disorders: An Overview Epidemiology Research International Volume 2011)
The majority of patients were diagnosed with dissociative motor disorder (43.3% outpatients, 37.7% inpatients), followed by dissociative convulsions (23% outpatients, 27.8% inpatients) Female preponderance was seen across all sub-types of dissociative disorder except dissociative fugue. Dissociative disorders in a psychiatric institute in India--a selected review and patterns over a decade
Etiological theories
Information processing theories In early 1970s, Hilgard -“ N eodissociation theory”. This theory conceptualizes the mental apparatus as consisting of a hierarchy of connected cognitive structures that monitor, organize and control thought and action. According to this theory, certain conditions can disrupt the links between structures, resulting in a reduction either of normal voluntary control over subordinate structures or in awareness of a body process controlled by a given structure .
Brown hypothesizes that conversion symptoms reflect the selection of inappropriate cognitive representation by low level attention. This selection takes place during the creation of primary representations that are understood to underlie both the activation of thought and active schemata, and the subjective experience and control of action.
Discrete behavioural state model Putnam put forward this model in late 1980s. He postulates “states” to be the fundamental unit of organization of consciousness. The concept of state/mental state is defined as “a constellation of certain patterns of physiological variables and/or patterns of behaviour which seem to repeat themselves and which appear to be relatively stable”.
Discrete mental- behavioural states can be detected in new born infants. When a transition of state occurs, the new state is reflected in the quantitative and qualitative variables that define it . According to his model, dissociative disorders are characterized by the individual’s consciousness being organized into a series of discrete mental- behavioural states characterized by specific affects, body images, modes of cognition, perceptions, memories and behaviour .
Unlike most adults, in individuals prone to dissociation, the transitions between the individual’s states remain abrupt and discontinuous. This can occur either as a result of severe childhood trauma that has disrupted the normal developmental process of smoothing out transitions between states, or in response to conditions of severe stress, terror, severe illness or fatigue
Dissociation as a response to trauma Since 1980s, research has elucidated multiple lines of evidence linking dissociative disorder with antecedent trauma. Several hundred peer-reviewed studies have found significantly high levels of dissociation in traumatized groups in comparison with the non-traumatized clinical and the general population. Van der Hart et al, 2004
Sar et al (2004) found childhood physical trauma in 44.7% and childhood sexual abuse in 26.3% in a sample of 38 patients with conversion disorder . Maaranen et al (2004) reported a strong association of childhood adverse experiences in people with somatoform dissociation. Stone et al (2004) reported a higher incidence of parental divorce in patients with pseudoseizures .
Taxon model Taxon items represent statistically derived clusters of symptoms experienced by those with a dissociative illness . It assumes that pathological dissociation such as dissociative identity disorder represents a different type of taxon of psychological organization. This is a contrast to earlier belief that dissociation occurs as a continuum from normal to pathological (Isaac & Chand, 2006; Loweinstein & Putnam, 2005 ).
The taxon model implies a significantly different developmental scenario than the continuum model, as well as a different approach to treatment . In a continuum model of dissociation, a positive treatment response would be conceptualized as moving a dissociative individual more toward the normal dissociation segment of the continuum. By contrast, a positive treatment outcome in a taxon model implies changing an individual’s type from the dissociative to the nondissociative category.
Hypnotic model This model hypothesizes that a traumatized individual uses his or her innate hypnotic capacity to induce autohypnosis as a defense against overwhelming or repetitive traumatic experiences . With continued use, the autohypnotic state is transformed into an independent alter personality state. Several lines of evidence are said to support the autohypnotic theory.
The first is that dissociative, especially dissociative identity disorder patients are highly hypnotizable. Second, many of the clinical phenomena associated with pathological dissociation, such as trance states, age regression, auditory hallucinations and amnesias, can be produced in normal individuals with hypnosis. Finally, a pair of studies suggested that childhood trauma might increase hypnotizability . ( Loweinstein & Putnam, 2005).
Somatic marker hypothesis This hypothesis was proposed by Damasio (2000). He developed a neurobiological model of consciousness and proposed that conversion reactions may reflect transient but radical changes in body maps, the neural representation of body states. The spinothalamic pathway conveys afferent interoceptive information from all tissues of the body and body state is mapped continuously at different brain levels (i.e., brainstem nuclei, hypothalamus, thalamus, anterior cingulated cortex and somatosensory cortices ).
Somatic marker hypothesis defines “feelings” as subjective perception of body state and feelings can emerge due to actual stimulation of emotion triggering sites.
Iatrogenic and sociocognitive model Some authorities believe that dissociative identity disorder and dissociative amnesia are not authentic psychiatric disorders but rather the product of suggestion on susceptible individuals that leads them to believe that they have a dissociative disorder and to enact the role of a person with multiple selves or amnesia for childhood maltreatment. This has been called the iatrogenic or sociocognitive model. However , no empirical studies have been performed in clinical population to attempt to examine the sociocognitive model or related ideas.
Neurobiology
Disorganized Attachment and the Orbitofrontal Cortex as the Basis for the Development of Dissociative Identity Disorder One particularly promising theory posits that, in addition to traumagenic origins, infant disorganized attachment may be a significant contributor to the development of DID . Neuroimaging studies have identified areas of the brain, the orbitofrontal cortex in particular, that function differently in DID patients, thus providing a neurobiological basis for the disorder.
One study compared rCBF of DID patients while they were in their host personality with normal controls and observed lower rCBF in the orbitofrontal cortex (OFC) of the DID subjects. The orbitofrontal cortex is thought to be involved in decision-making. Thus, Sar hypothesizes that the decreased functioning of the OFC results in impulsivity and that the switch to an alter personality may represent a drastic expression of impulsive behavior caused by cognitive and emotional conflicts.
A more adequate description, provided by Rhawn Joseph, is that the OFC is the “senior executive of the emotional brain. This system is also involved in the regulation of the body state and reflects changes taking place in that state (Luria, 1980 ). Antonio Damasio posits in his model of consciousness that the development of a notion of self arises from the brain’s second order mapping of the relation between “objects” and the organism.
Within this model of consciousness, the OFC, with its functions in both emotional processing of sensory information as well as homeostasis and the mapping of the body, would seem to be a critical component in the generation of a self. Thus , it is quite plausible that an abnormally functioning OFC could lead to the generation of multiple selves .
Attachment theory posits that an infant’s development of attachment to its caregiver, usually its parent(s), plays a large role in the development of its personality and later social behaviors. Liotti builds upon the work of Main and Hesse by hypothesizing that the conflicting models of self that are developed within an infant with disorganized attachment create the risk for the later development of DID.
The conflicting attachment experiences endured by an infant with disorganized attachment would lead to irregular development of the OFC, which would mirror the development of the conflicting models of self. American Psychiatric Association, STAT!Ref , and Teton Data Systems. Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Association, 2000
Neurophysiology studies HRV, EEG and (functional) MRI are sensitive methods to detect physiological changes related to dissociation and dissociative disorders such as FNSS. The majority of the identified studies concerned the physiological characteristics of hypnosis; relatively few investigations on dissociation related FNSS were identified. General findings were increased parasympathetic functioning during hypnosis (as measured by HRV), and lower HRV in patients with FNSS
Flor -Henry et al (1990) documented two cases of multiple personality disorder with bilateral frontal and left temporal dysfunction on neuropsychological test batteries and relative activation of the left hemisphere across all cerebral regions in EEG analysis
Allen & Movius (2000) documented four cases of multiple personality disorder evaluated by ERP during a memory assessment task, in which words learned by one identity were then presented to a second identity. All patients, when tested as second personality, produced ERP and behavioural evidence consistent with recognition of material learned by the first identities.
Neurochemical studies Delahanty et al (2003) found that peritraumatic dissociation was correlated with 15 hour urine epinephrine level in 59 motor vehicle accident patients. Such a correlation was not found for norepinephrine. Simeon et al (2003) found strong negative correlation between urinary norepinephrine and depersonalization scores in patients with depersonalization disorder.
The authors concluded that although dissociation accompanied by anxiety was associated with heightened noradrenergic tone, there was a marked basic norepinephrine decline with increasing severity of dissociation . Chambers et al (1999) found that high doses of ketamine produced slowed perception of time, tunnel vision, derealization and depersonalization in trauma victims .
Pretreatment with a benzodiazepine or lamotrigine reduced but didn’t entirely eliminate the effects of ketamine. It suggests that NMDA glutamate receptors play a central role in dissociative symptoms
neuroimaging key findings in neuroimaging studies of dissociative disorder are volume reduction of amygdala and hippocampus, nondominant hemisphere lesions in dissociative seizure. There is increase as well as decrease in contralateral hemisphere activity in motor conversion disorder. In one study, patients with depersonalization disorder had higher activity in somatosensory association areas Simeon et al 2000
In another study, functional MRI was used to examine brain activation in PTSD patients in a dissociative state while reexperiencing traumatic memories; greater activation was found in the temporal, inferior, and medial frontal regions and in occipital, parietal, anterior cingulate, and medial prefrontal cortical regions. Lanius RA , Brain activation during script-driven imagery induced dissociative responses in PTSD: a functional magnetic resonance imaging investigation. Biol Psychiatry. 2002
Administration of ketamine, an antagonist of N -methyl-D-aspartic acid (NMDA) receptors, which are highly concentrated in the hippocampus, resulted in dissociative symptoms in healthy subjects, including feelings of being out of body and of time standing still, perceptions of body distortions, and amnesia. On the basis of these findings, it was hypothesized that stress, acting through NMDA receptors in the hippocampus, may mediate symptoms of dissociation. Glutamate and post-traumatic stress disorder: toward a psychobiology of dissociation. Semin Clin Neuropsychiatry. 1999
Dissociation scales and diagnostic interviews Symptom screening measures Dissociative experience scale (DES) is one of the best known among general dissociation screening scales. Developed by Bernstein & Putnam (1986), Dissociative Experiences Scale (DES) is a 28-item self-report instrument. It is a visual analog scale where the respondent has to slash a line to indicate a score anywhere from 0 to 100 for each item .
Another good screening measure is the 20-item Somatoform Dissociative Questionnaire (SDQ-20) developed by Nijenhuis et al (1996 ). The scale taps many of the somatosensory and dissociative symptoms including motor inhibitions, loss of function, anaesthesia and analgesia, pain and problems with vision, hearing and smell. The scale has good reliability and validity for discriminating dissociative disorder patients.
Diagnostic interviews Two DSM-based structured interviews have been developed for the formal diagnosis of dissociative disorders- The Structured Clinical Interview for DSM-IV Dissociative Disorders, Revised ( SCID-D-R; Steinberg et al, 1994) The Dissociative Disorder Interview Schedule (DDIS; Ross et al, 1989).
The SCID-D-R is a semi-structured clinician administered interview that assesses the presence and severity of amnesia, identity confusion and alteration, depersonalization and derealization . The DDIS is a clinical diagnostic instrument which inquires about a wide range of phenomena in addition to dissociative symptoms, including child abuse history, major depression, somatic complaints, substance abuse and paranoid experiences
Clinical features
Dissociative amnesia There are two major clinical presentations of dissociative amnesia- The classic presentation is an overt, florid dramatic clinical disturbance in which an individual is found without memory for identity or life history. Less extreme forms of amnesia, such as acute amnesia for recent traumatic circumstances, such as combat or rape, also fall into this category.
In the non-classical presentation, chronic, recurrent or persistent dissociative amnesia, or a combination of these, is most likely. Commonly , patients with nonclassic presentation of amnesia do not reveal the presence of dissociative symptoms unless directly asked about those.
subtypes Localized -inability to recall events related to a circumscribed period of time. Selective -ability to remember some, but not all, of the events during a circumscribed period of time . Continuous-failure to recall successive events as they occur Generalized-failure to recall whole life of the patient. Systematized-amnesia for certain categories of memory such as all memories relating to one’s family or a particular person .
It is important to distinguish dissociative amnesia from organic amnesia. Though there is no single test or examination that can differentiate these two, in organic amnesia , the memory loss for personal information is embedded in a far more extensive set of cognitive, language, attentional , behavioural and memory problems. Loss of memory for personal identity is usually not found in organic amnesia without evidence of a marked disturbance in many domains of cognitive function .
Dissociative fugue Classically , three types of fugue have been described : ( 1) fugue with awareness of loss of personal identity (2 ) fugue with change of personal identity (3 ) fugue with retrograde amnesia . During a fugue, patients often appear without psychopathology and do not attract attention. After the termination of a fugue, the patient may experience perplexity, trance-like behaviour , depersonalization, derealization , and conversion symptoms, in addition to amnesia .
Dissociative identity disorder Dissociative identity disorder is characterized by two or more distinctive identities or personalities; at least two of these identity states recurrently taking control of the person’s behaviour and inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness (APA, 1994 ). The different identities, referred to as alters , may exhibit differences in speech, mannerisms, attitudes, thoughts, and gender orientation
Most patients have personalities that are named, but there may be those who are nameless or whose appellations are not proper names. The classic host personality, which usually (over 50% of the time) presents for treatment, nearly always bear the legal name and is depressed, anxious, somewhat neurasthenic, compulsively good, masochistic, conscience- striken , constricted hedonically and suffers both psychophysiological symptoms and time loss or time distortion.
Depersonalization disorder Patients experiencing depersonalization often have great difficulty expressing what they are feeling. There are a number of distinct components to the experience of depersonalization. These include a sense of bodily changes, a sense of being cut off from others, and a sense of being cut off from one’s own emotions. Despite the outward appearance of lack of distress, depersonalization disorder patients are enduring an intensely unpleasant, and often disabling, subjective experience .
Serotonergic involvement Association of depersonalization with migraines and marijauna , response to selective serotonin reuptake inhibitors drugs,increased depersonalization symptom seen with depletion of tryptophan. Neurochemical findings have suggested possible involvement of serotonergic, endogenous opioid and glutamatergic NMDA pathways . Depersonalisation disorder: a contemporary overview, Simeon D
On the other hand, de-realization , is the sense that the world appears strange, foreign, or dream-like. It is conceptualized as a dissociative alteration in the perception of the environment. Objects may appear as if viewed from a great distance and as if they are two dimensional, without depth or substance.
Objects feel strange to the touch,Colours deem and lose their vitality. The faces of others change, becoming unfamiliar or frightening. The world and all action and behaviour lose meaning and purpose .
Several models have been proposed to explain depersonalization disorder. A schematic integration of these MODEL
Dissociative disorder of movement and sensation (Conversion disorder) In these disorders, motor symptoms or deficits usually include impaired coordination, tremor or flaccidity, difficulty swallowing or a sensation of lump in the throat, aphonia and urinary retention. Sensory symptoms or deficits include loss of touch or pain sensation, hyperesthesia and paresthesia , double vision, blindness, deafness and hallucination.
Dissociative seizure can be distinguished from true seizure by its occurrence in almost always awake condition, longer duration, lack of stereotyped movements, variable and bizarre motor activity, partial preservation of awareness, pelvic thrusting movements, side to side head movement, emotional display, closed eyes with resistance to passive opening, responsiveness to painful stimuli, absence of postictal confusion, normal postictal EEG and normal serum prolactin level after seizure. Bowman & Markand , 2005
OTHER SPECIFIED DISSOCIATIVE DISORDER This category is included for disorders in which the predominant feature is a dissociative symptom (i.e., a disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment) that does not meet the criteria for any specific dissociative disorder. It includes – 1.Chronic and recurrent syndromes of mixed dissociative symptoms
2.Identity disturbance due to prolonged and intense coercive persuasion. 3.Acute dissociative reactions to stressful events 4.Dissociative trance-manifest by temporary marked alteration in the state of consciousness or by a loss of customary sense of personal identity but without the replacement by an alternate sense of identity.
references Kaplan & sadock’s comprehensive textbook of psychiatry,ninth edition Kaplan & sadock's synopsis of psychiatry: behavioral sciences/clinical psychiatry, 10th edition Glutamate and post-traumatic stress disorder: toward a psychobiology of dissociation. semin clin neuropsychiatry. 1999 Lanius ra , brain activation during script-driven imagery induced dissociative responses in ptsd : a functional magnetic resonance imaging investigation. biol psychiatry. 2002 Epidemiology of dissociative disorders: an overview,epidemiology research international volume 2011)