Dissociative identity disorder

Essential Features:

• Disruption of identity characterized by the presence of two or more distinct personality states (dissociative identities), involving marked discontinuities in the sense of self and agency. Each personality state includes its own pattern of experiencing, perceiving, conceiving, and relating to self, the body, and the environment.
• At least two distinct personality states recurrently take executive control of the individual’s consciousness and functioning in interacting with others or with the environment, such as in the performance of specific aspects of daily life (e.g., parenting, work), or in response to specific situations (e.g., those that are perceived as threatening).
• Changes in personality state are accompanied by related alterations in sensation, perception, affect, cognition, memory, motor control, and behaviour. There are typically episodes of amnesia inconsistent with ordinary forgetting, which may be severe.
• The symptoms are not better accounted for by another mental disorder (e.g., Schizophrenia or Other Primary Psychotic Disorder).
• The symptoms are not due to the effects of a substance or medication on the central nervous system, including withdrawal effects (e.g., blackouts or chaotic behaviour during substance intoxication), and are not due to a Disease of the Nervous System (e.g., complex partial seizures) or to a Sleep-Wake disorder (e.g., symptoms occur during hypnagogic or hypnopompic states).
• The symptoms result in significant impairment in personal, family, social, educational, occupational or other important areas of functioning. If functioning is maintained, it is only through significant additional effort.

Additional Clinical Features:

• Alternation between distinct personality states is not always associated with amnesia. That is, one personality state may have awareness and recollection of the activities of another personality state during a particular episode. However, substantial episodes of amnesia are typically present at some point during the course of the disorder.
• In individuals with Dissociative Identity Disorder, it is common for one personality state to be ‘intruded upon’ by aspects of other non-dominant, alternate personality states without their taking executive control, as in Partial Dissociative Identity Disorder. These intrusions may involve a range of features, including cognitive (intruding thoughts), affective (intruding affects such as fear, anger, or shame), perceptual (e.g., intruding voices or fleeting visual perceptions), sensory (e.g., intruding sensations such as being touched, pain, or altered perceived size of the body or of part of the body), motor (e.g., involuntary movements of an arm and hand), and behavioural (e.g., an action that lacks a sense of agency or ownership). The personality state that is intruded upon in this way commonly experiences the intrusions as aversive, and may or may not realize that the intrusions relate to features of other personality states.
• Dissociative Identity Disorder is commonly associated with serious or chronic traumatic life events, including physical, sexual, or emotional abuse.

Boundary with Normality (Threshold):

• The presence of two or more distinct personality states does not always indicate the presence of a mental disorder. In certain circumstances (e.g., as experienced by ‘mediums’ or other culturally accepted spiritual practitioners) the presence of multiple personality states is not experienced as aversive and is not associated with impairment in functioning. A diagnosis of Dissociative Identity Disorder should not be assigned in these cases.

Course Features:

• Onset of Dissociative Identity Disorder is most commonly associated with traumatic experiences, especially physical, sexual, and emotional abuse or childhood neglect. The onset of identity changes can also be triggered by removal from ongoing traumatizing circumstances, death or serious illness of the perpetrator of abuse, or by other unrelated traumatic experiences later in life.
• Dissociative Identity Disorder usually has a recurrent and fluctuating clinical course.
• Some individuals remain highly impaired in most aspects of functioning, despite treatment. Individuals with Dissociative Identity Disorder are at high risk for self-injurious behaviour and suicide attempts.
• Although symptoms can spontaneously remit with age, recurrence may occur during periods of increased stress.
• Recurrent or chronic ongoing traumatic experiences are associated with poorer prognosis.
• Dissociative Identity Disorder often co-occurs with other mental disorders. In such cases, identity alternations can influence the symptom presentation of the co-occurring disorders.

Developmental Presentations:

• Onset of Dissociative Identity Disorder can occur across the lifespan. Initial identity changes usually appear at an early age, but dissociative identities are not typically fully developed. Instead, children present with discontinuities of experience and marked interference among mental states.
• Identification of Dissociative Identity Disorder in children can be difficult because symptoms manifest in a variety of ways that overlap with other mental disorders, including those involving conduct problems, mood and anxiety symptoms, learning difficulties, and auditory hallucinations. Young children often project their dissociated identities onto toys or other objects, so that abnormalities in their identity may only become detectable as children age and their behaviours become less developmentally appropriate. With adequate treatment, children with Dissociative Identity Disorder tend to have a better prognosis than adults.
• Early identity changes in adolescence characteristic of Dissociative Identity Disorder may be mistaken for developmentally typical difficulties with emotional and behavioural regulation.
• Older patients with Dissociative Identity Disorder may present with what appears to be late-life onset paranoia or cognitive impairment, or atypical mood, psychotic or obsessive-compulsive symptoms.

Culture-Related Features:

• Features of Dissociative Identity Disorder can be influenced by the individual’s cultural background. For example, individuals may present with dissociative symptoms of movement, behaviour, or cognition – such as non-epileptic seizures and convulsions, paralyses, or sensory loss – in socio-cultural settings where such symptoms are common. These symptoms typically remain persistent and debilitating until the underlying Dissociative Identity Disorder is identified and treated.
• Acculturation or prolonged intercultural contact may shape the characteristics of the dissociative identities; for example, identities in India may speak English exclusively and wear Western clothes as a sign of their difference from the usual personality state.
• In some societies, presentations of Dissociative Identity Disorder may occur after stressful exposures (e.g., recurrent parental affect dysregulation), which may or may not involve physical or sexual abuse. The tendency toward dissociative responses to stressors may be increased in cultures with less individualistic (‘bounded’) conceptions of the self or in circumstances of socioeconomic deprivation.

Sex- and/or Gender-Related Features:

• Prior to puberty, prevalence of Dissociative Identity Disorder does not appear to vary by gender. After puberty, prevalence appears to be higher in females.
• Significant gender differences have been observed in the symptoms of Dissociative Identity Disorder across the lifespan. Females with Dissociative Identity Disorder often present with more dissociative identities and tend to experience more acute dissociative states (e.g., amnesia, conversion symptoms, self-mutilation) than males. Males with Dissociative Identity Disorder are more likely to deny their symptoms or exhibit violent or criminal behaviours.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Trance Disorder and Possession Trance Disorder: Trance Disorder is not characterized by the presence of two or more distinct personality states. In Possession Trance Disorder, the individual’s customary sense of personal identity is replaced by an external ‘possessing’ identity, which is attributed to the influence of a spirit, power, deity or other spiritual entity. Behaviours or movements are experienced as being controlled by the possessing agent. Individuals who describe both internal distinct personality states that assume executive control as well as episodes of being controlled by an external possessing identity should receive a diagnosis of Dissociative Identity Disorder rather than Possession Trance Disorder.
• Boundary with Partial Dissociative Identity Disorder: In Dissociative Identity Disorder, discontinuities in agency and sense of self are marked (manifested in episodes of executive control, often including amnesia, and greater elaboration of the personality states), whereas in Partial Dissociative Identity Disorder these discontinuities are less pronounced. In Partial Dissociative Identity Disorder, one personality state is dominant and functions in daily life (e.g., parenting, work), but is intruded upon by non-dominant personality states (dissociative intrusions). Unlike in Dissociative Identity Disorder, the non-dominant personality states do not recurrently take executive control of the individual’s consciousness and functioning to the extent that they perform in specific aspects of daily life (e.g., parenting, work). However, in Partial Dissociative Identity Disorder, there may be occasional, limited and transient episodes in which a distinct personality state assumes executive control to engage in circumscribed behaviours (e.g., in response to extreme emotional states, episodes of self-harm, or the reenactment of traumatic memories). In Partial Dissociative Identity Disorder, the non-dominant personality states are not elaborated to the extent observed in Dissociative Identity Disorder. For example, they may not be oriented to the present, may have the identity of a child, or may be mostly or exclusively involved in reenacting traumatic memories. In addition, there are typically (although not always) significant episodes of amnesia in Dissociative Identity Disorder, which may be severe. In contrast, episodes of amnesia in Partial Dissociative Identity Disorder, if present, are typically brief and restricted to extreme emotional states or episodes of self-harm.
• Boundary with other Dissociative Disorders: Dissociative Identity Disorder is distinguished from other Dissociative Disorders by the presence of two distinct personality states that recurrently take executive control of the individual’s consciousness and functioning. This does not occur in any other dissociative disorder (except possibly for limited circumstances in Partial Dissociative Identity Disorder, as described above). An additional Dissociative Disorder diagnosis should not be assigned based on phenomena that occur in specific relationship to changes in personality states (e.g., memory loss, changes in motor or sensory functioning, experiences of depersonalization and derealization).
• Boundary with Schizophrenia or Other Primary Psychotic Disorders: Individuals with Dissociative Identity Disorder may report experiencing symptoms such as hearing voices or intrusive thoughts that may also occur in Schizophrenia or Other Primary Psychotic Disorders. However, individuals with Dissociative Identity Disorder do not typically exhibit delusions, formal thought disorder, or negative symptoms (as in Schizophrenia or Schizoaffective Disorder) or rapid onset and rapidly fluctuating symptoms (as in Acute and Transient Psychotic Disorder). In the absence of other symptoms supporting a diagnosis of Schizophrenia or Other Primary Psychotic Disorder, intrusive phenomena such as hearing voices may suggest the presence of dissociative personality states.
• Boundary with Post-Traumatic Stress Disorder and Complex Post-Traumatic Stress Disorder: Individuals with Post-Traumatic Stress Disorder and Complex Post-Traumatic Stress Disorder may experience alterations in identity and sense of agency during episodes of re-experiencing of traumatic events (e.g., during flashbacks). For example, they may feel that they are unable to control their experiences or reactions during the re-experiencing episode or that they are in a different time in their own lives. However, these episodes are not characterized by a distinct personality state taking executive control of the individual’s consciousness and functioning. Because Dissociative Identity Disorder is commonly associated with serious or chronic traumatic life events, it may co-occur with Post-Traumatic Stress Disorder or Complex Post-Traumatic Stress Disorder, and both diagnoses may be assigned if the full diagnostic requirements for both disorders are met.
• Boundary with Obsessive-Compulsive Disorder: Obsessive-Compulsive Disorder involves repetitive and persistent thoughts (e.g., of contamination), images (e.g., of violent scenes), or impulses/urges (e.g., to stab someone) that are experienced as intrusive and unwanted (obsessions) as well as repetitive behaviours, including repetitive mental acts, that the individual feels driven to perform (compulsions). However, Obsessive-Compulsive Disorder is not characterized by discontinuities in the sense of self and agency or the presence of two or more distinct personality states.
• Boundary with Personality Disorder: Personality Disorder, particularly with Borderline pattern, is characterized by persistent disturbances in sense of identity and self-direction, and often by problems with affect regulation. Personality Disorder does not involve the presence of two or more distinct personality states, but some individuals with Severe Personality Disorder exhibit transient dissociative experiences during times of stress or intense emotion.