Dissociative disorder
Dissociative disorders are a range of mental disorders characterized by significant disruptions or fragmentation "in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behavior." Dissociative disorders involve involuntary dissociation as an unconscious defense mechanism, wherein the individual with a dissociative disorder experiences separation in these areas as a means to protect against traumatic stress. Some dissociative disorders are caused by major psychological trauma, though the onset of depersonalization-derealization disorder may be preceded by less severe stress, by the influence of psychoactive substances, or occur without any discernible trigger.
Classification
Of frameworks for classification of mental disorders, the two most prominent are the Diagnostic and Statistical Manual of Mental Disorders and the International Classification of Diseases; the latest versions of these are the DSM-5-TR and ICD-11, respectively.The DSM-IV category of dissociative disorder not otherwise specified has been split into two diagnoses: other specified dissociative disorder and unspecified dissociative disorder. These categories are used for forms of pathological dissociation that do not fully meet the criteria of the other specified dissociative disorders; or if the correct category has not been determined; or the disorder is transient. Other specified dissociative disorder has multiple types, which OSDD-1 falling on the spectrum of dissociative identity disorder; it is known as partial DID in the International Classification of Diseases.
The dissociative disorders listed in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition are as follows:
Dissociative identity disorder
Dissociative amnesia
Depersonalization-derealization disorder
Others
was previously a separate category but is now treated as a specifier for dissociative amnesia, though many patients with dissociative fugue are ultimately diagnosed with dissociative identity disorder.The ICD-11 lists dissociative disorders as:
- Dissociative neurological symptom disorder
- Dissociative amnesia
- Dissociative amnesia with dissociative fugue
- Trance disorder
- Possession trance disorder
- Dissociative identity disorder
- Partial dissociative identity disorder
- Depersonalization-derealization disorder
Causes
Dissociative identity disorder
The cause of dissociative identity disorder is contentious; it is most often considered to be caused either by ongoing childhood trauma that occurs before the ages of six to nine, or as an unintentional product of therapy, fantasy, or other sociogenic factors.Dissociative amnesia
This disorder is caused by psychological trauma. While a history of child abuse is common in patients, it is not a necessary factor in determining if a person will develop dissociative amnesia.Depersonalization-derealization disorder
While not as strongly linked as other dissociative disorders, there is a correlation between depersonalization-derealization disorder and childhood trauma, especially emotional abuse or neglect. It can also be caused by other forms of stress such as sudden death of a loved one.Mechanism
Differences in brain activity
Dissociative disorders are characterized by distinct brain differences in the activation of various brain regions including the inferior parietal lobe, prefrontal cortex, and limbic system.Those with dissociative disorders have higher activity levels in the prefrontal lobe and a more inhibited limbic system on average than healthy controls. Heightened corticolimbic inhibition is associated with distinctly dissociative symptoms such as depersonalization and derealization. The function of these symptoms is thought to be a coping mechanism employed in extremely threatening or traumatic events. By inhibiting structures in the limbic system, such as the amygdala, the brain is able to reduce extreme levels of arousal. In the dissociative subtype of PTSD, there is both excessive control of emotions through suppressed limbic structures and insufficient control of emotions in the hyperactivity of the medial prefrontal cortex. Increased activity in the medial prefrontal cortex is associated with non-dissociative symptoms such as re-experiencing and hyperarousal.
Differences in volume of brain structures
There are notable differences in the volume of certain areas of the brain such as reduced cortical and subcortical volumes in the hippocampus and amygdala. Reduced volume of the amygdala may account for the lessened emotional reactivity observed during dissociation. The hippocampus is associated with learning and the formation of memory, and its reduced volume is associated with impairments in memory for those with DID and PTSD. Brain-imaging studies demonstrating the link between reduced hippocampal volume and DID as well as PTSD have added to empirical support for the existence of the disorder, as additional brain-imaging studies have demonstrated a negative correlation between hippocampal volume and early childhood trauma.Diagnosis
Diagnosis can be made with the help of structured clinical interviews such as the Dissociative Disorders Interview Schedule and the Structured Clinical Interview for DSM-IV Dissociative Disorders, and behavioral observation of dissociative signs during the interview. Additional information can be helpful in diagnosis, including the Dissociative Experiences Scale or other questionnaires, performance-based measures, records from doctors or academic records, and information from partners, parents, or friends. A dissociative disorder cannot be ruled out in a single session and it is common for patients diagnosed with a dissociative disorder to not have a previous dissociative disorder diagnosis due to a lack of clinician training. Some diagnostic tests have also been adapted or developed for use with children and adolescents such as the Adolescent Dissociative Experiences Scale, Children's Version of the Response Evaluation Measure, Child Interview for Subjective Dissociative Experiences, Child Dissociative Checklist, Child Behavior Checklist Dissociation Subscale, and the Trauma Symptom Checklist for Children Dissociation Subscale.There are problems with classification, diagnosis and therapeutic strategies of dissociative and conversion disorders which can be understood by the historic context of hysteria. Even current systems used to diagnose DD such as the DSM-IV and ICD-10 differ in the way the classification is determined. In most cases mental health professionals are still hesitant to diagnose patients with Dissociative Disorder, because before they are considered to be diagnosed with Dissociative Disorder these patients have more than likely been diagnosed with major depressive disorder, anxiety disorder, and most often post-traumatic stress disorder. It has been found from interviews with those who may be afflicted with dissociative disorders may be more effective at getting an accurate diagnosis than self-scoring assessments and scales.
An important concern in the diagnosis of dissociative disorders in forensic interviews is the possibility that the patient may be feigning symptoms in order to escape negative consequences. Young criminal offenders report much higher levels of dissociative disorders, such as amnesia. In one study it was found that 1% of young offenders reported complete amnesia for a violent crime, while 19% claimed partial amnesia. There have also been cases in which people with dissociative identity disorder provide conflicting testimonies in court, depending on the personality that is present.
The world-wide prevalence of dissociative disorders is not well understood due to different cultural beliefs surrounding human emotions and the human brain.
Treatment
There are no medications to cure or completely treat dissociative disorders, however, drugs to treat anxiety and depression that may accompany the disorders can be given.Dissociative identity disorder
This disorder i treated by means of long-term psychotherapy to improve the patient's quality of life. Psychotherapy often involves hypnosis, creative art therapy, cognitive therapy, and medications. These medications can help control the symptoms associated with DID and other DD, but there are no medications yet that specifically treat dissociative disorders.Dissociative amnesia
Psychotherapy counseling or psychosocial therapy for this disorder involves talking about the disorder and related issues with a mental health provider. The medication pentothal can sometimes help to restore the memories. The length of an event of dissociative amnesia may be a few minutes or several years. If an episode is associated with a traumatic event, the amnesia may clear up when the person is removed from the traumatic situation.Depersonalization-derealization disorder
For this disorder, the same treatment as for dissociative amnesia is utilized. An episode of depersonalization-derealization disorder can be as brief as a few seconds or continue for several years.Epidemiology
Prevalence
The lifetime prevalence of dissociative disorders varies from 10% in the general population to 46% in psychiatric inpatients.Dissociative disorders have been found to be quite prevalent in outpatient populations, as well as within low-income communities. One study found that in a population of poor inner-city outpatients, there was a 29% prevalence of dissociative disorders.
The prevalence of dissociative disorders is not completely understood due to the many difficulties in diagnosing dissociative disorders. Many of these difficulties stem from a misunderstanding of dissociative disorders, from an unfamiliarity diagnosis or symptoms to disbelief in some dissociative disorders entirely. Due to this it has been found that only 28% to 48% of people diagnosed with a dissociative disorder receive treatment for their mental health. Patients who are misdiagnosed are often those more likely to be hospitalised repeatedly, and lack of treatment can result in intensive outpatient treatment and higher rates of disability.