Partial dissociative identity disorder

Essential Features:

• Disruption of identity characterized by the experience of two or more distinct personality states (dissociative identities), involving 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.
• One personality state is dominant and functions in daily life (e.g., parenting, work), but is intruded upon by one or more non-dominant personality states (dissociative intrusions). These intrusions may be cognitive (intruding thoughts), affective (intruding affects such as fear, anger, or shame), perceptual (e.g., intruding voices fleeting visual perceptions, sensations such as being touched), motor (e.g., involuntary movements of an arm), or behavioural (e.g., an action that lacks a sense of agency or ownership). These experiences are experienced as interfering with the functioning of the dominant personality state and are typically aversive.
• 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, 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 or during episodes of self-harm or the reenactment of traumatic memories).
• 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:

• The dissociative intrusions attributed to non-dominant personality states by individuals with Partial Dissociative Identity Disorder are experienced internally and may not be obvious to observers. Observable identity alteration is typically indicative of Dissociative Identity Disorder.
• Individuals with Partial Dissociative Identity Disorder often do not experience amnesia during episodes of dissociative intrusions. If amnesia does occur, it is usually brief and restricted to extreme emotional states or episodes of self-harm.
• Partial 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 distinct personality states or dissociative intrusions 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 Partial Dissociative Identity Disorder should not be assigned in these cases.

Course Features:

• Partial Dissociative Identity Disorder is strongly linked to 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.
• Partial Dissociative Identity Disorder usually has a recurrent and fluctuating clinical course. Although symptoms might spontaneously reduce with age in older adults, periods of increased stress can cause recurrence of symptoms. Factors such as re-traumatization or chronically ongoing abuse tend to predict a poorer prognosis.
• Partial 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:

• Disorganized attachment in childhood might put individuals at risk of developing Partial Dissociative Identity Disorder later in life.
• The onset of Partial Dissociative Identity Disorder may occur at any stage of life, from early childhood to late adulthood.
• Diagnosis in preadolescent children might be particularly challenging as Partial Dissociative Identity Disorder in children can manifest in a variety of ways, including conduct problems, mood and anxiety symptoms, learning difficulties, or what appear to be auditory hallucinations. Also, young children often project their dissociated identities onto toys or other objects, so that abnormalities in their identity may become detectable only as children age and their behaviours become less developmentally appropriate. Given adequate treatment, childhood cases of Partial Dissociative Identity Disorder tend to have a better prognosis than adult cases.
• Early identity changes in adolescence characteristic of Partial Dissociative Identity Disorder may be mistaken for developmentally typical difficulties with emotional and behavioural regulation.
• Older patients with Partial Dissociative Identity Disorder may present with what appears to be late-life paranoia, cognitive dysfunction, atypical mood, psychotic symptoms, or obsessive-compulsive symptoms.

Culture-Related Features:

• Features of Partial 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 sociocultural settings where such symptoms are common.
• In some societies, presentations of Partial 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:

• Females appear to be more likely than males to experience identity intrusions.

Boundaries with Other Disorders and Conditions (Differential Diagnosis):

• Boundary with Trance Disorder and Possession Trance Disorder: Some dissociative intrusions in Partial Dissociative Identity Disorder may resemble trance states, but Trance Disorder is not characterized by the presence of two or more distinct personality states. In Possession Trance Disorder, the individual’s normal 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 experience dissociative intrusions attributed to both internal and external entities should receive a diagnosis of Partial Dissociative Identity Disorder rather than Possession Trance Disorder.
• Boundary with 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 Dissociative Identity Disorder, two or more distinct personality states recurrently take executive control of the individual’s consciousness and functioning to the extent that they function in daily life or engage in relatively elaborate patterns of behaviour in specific situations. In contrast, in Partial Dissociative Identity Disorder, the non-dominant, alternate 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, although 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 alternate 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. Furthermore, in Dissociative Identity Disorder there are typically (although not always) significant episodes of amnesia, which may be severe. In Partial Dissociative Identity Disorder, amnesia, if present, is usually brief and restricted to extreme emotional states or episodes of self-harm.
• Boundary with other Dissociative Disorders: Partial Dissociative Identity Disorder is distinguished from other Dissociative Disorders by the presence of two or more distinct personality states. This does not occur in any other Dissociative Disorder (except Dissociative Identity Disorder, as described above). An additional Dissociative Disorder diagnosis should not be assigned based on phenomena that occur in specific relationship to intrusions by non-dominant 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 Partial 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 Partial Dissociative Identity Disorder do not typically exhibit delusions, formal thought disorder, or negative symptoms 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 and Other Primary Psychotic Disorder, intrusive phenomena such as hearing voices may suggest the presence of dissociative personality states.
• 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 Post-Traumatic Stress Disorder and Complex Post-Traumatic Stress Disorder: Partial Dissociative Identity Disorder involves pervasive alterations in identity and sense of agency. In Post-Traumatic Stress Disorder and Complex Post-Traumatic Stress Disorder, such alterations can occur but are limited to episodes of re-experiencing traumatic events (e.g., during flashbacks). If symptoms consistent with dissociative intrusions occur exclusively during such episodes in the context of Post-Traumatic Stress Disorder or Complex Post-Traumatic Stress Disorder, an additional diagnosis of Partial Dissociative Identity Disorder is not warranted.
• 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.